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Glossary
********

Abbrev
     An abbrev is a text string which expands into a different text
     string when present in the buffer.  For example, you might define
     a few letters as an abbrev for a long phrase that you want to
     insert frequently.  *Note Abbrevs::.

Aborting
     Aborting means getting out of a recursive edit (q.v.).  The
     commands `C-]' and `M-x top-level' are used for this.  *Note
     Quitting::.

Alt
     Alt is the name of a modifier bit which a keyboard input character
     may have.  To make a character Alt, type it while holding down the
     ALT key.  Such characters are given names that start with `Alt-'
     (usually written `A-' for short).  (Note that many terminals have a
     key labeled ALT which is really a META key.)  *Note Alt: User
     Input.

Auto Fill Mode
     Auto Fill mode is a minor mode in which text that you insert is
     automatically broken into lines of fixed width.  *Note Filling::.

Auto Saving
     Auto saving is the practice of saving the contents of an Emacs
     buffer in a specially-named file, so that the information will not
     be lost if the buffer is lost due to a system error or user error.
     *Note Auto Save::.

Backup File
     A backup file records the contents that a file had before the
     current editing session.  Emacs makes backup files automatically
     to help you track down or cancel changes you later regret making.
     *Note Backup::.

Balance Parentheses
     Emacs can balance parentheses manually or automatically.  Manual
     balancing is done by the commands to move over balanced expressions
     (*note Lists::.).  Automatic balancing is done by blinking or
     highlighting the parenthesis that matches one just inserted (*note
     Matching Parens: Matching.).

Bind
     To bind a key sequence means to give it a binding (q.v.).  *Note
     Rebinding::.

Binding
     A key sequence gets its meaning in Emacs by having a binding,
     which is a command (q.v.), a Lisp function that is run when the
     user types that sequence.  *Note Binding: Commands.  Customization
     often involves rebinding a character to a different command
     function.  The bindings of all key sequences are recorded in the
     keymaps (q.v.).  *Note Keymaps::.

Blank Lines
     Blank lines are lines that contain only whitespace.  Emacs has
     several commands for operating on the blank lines in the buffer.

Buffer
     The buffer is the basic editing unit; one buffer corresponds to
     one text being edited.  You can have several buffers, but at any
     time you are editing only one, the `selected' buffer, though
     several can be visible when you are using multiple windows (q.v.).
     Most buffers are visiting (q.v.) some file.  *Note Buffers::.

Buffer Selection History
     Emacs keeps a buffer selection history which records how recently
     each Emacs buffer has been selected.  This is used for choosing a
     buffer to select.  *Note Buffers::.

Button Down Event
     A button down event is the kind of input event generated right
     away when you press a mouse button.  *Note Mouse Buttons::.

`C-'
     `C-' in the name of a character is an abbreviation for Control.
     *Note C-: User Input.

`C-M-'
     `C-M-' in the name of a character is an abbreviation for
     Control-Meta.  *Note C-M-: User Input.

Case Conversion
     Case conversion means changing text from upper case to lower case
     or vice versa.  *Note Case::, for the commands for case conversion.

Character
     Characters form the contents of an Emacs buffer; see *Note Text
     Characters::.  Also, key sequences (q.v.) are usually made up of
     characters (though they may include other input events as well).
     *Note User Input::.

Click Event
     A click event is the kind of input event generated when you press a
     mouse button and release it without moving the mouse.  *Note Mouse
     Buttons::.

Command
     A command is a Lisp function specially defined to be able to serve
     as a key binding in Emacs.  When you type a key sequence (q.v.),
     its binding (q.v.) is looked up in the relevant keymaps (q.v.) to
     find the command to run.  *Note Commands::.

Command Name
     A command name is the name of a Lisp symbol which is a command
     (*note Commands::.).  You can invoke any command by its name using
     `M-x' (*note M-x::.).

Comment
     A comment is text in a program which is intended only for humans
     reading the program, and which is marked specially so that it will
     be ignored when the program is loaded or compiled.  Emacs offers
     special commands for creating, aligning and killing comments.
     *Note Comments::.

Compilation
     Compilation is the process of creating an executable program from
     source code.  Emacs has commands for compiling files of Emacs Lisp
     code (*note Byte Compilation: (elisp)Byte Compilation.) and
     programs in C and other languages (*note Compilation::.).

Complete Key
     A complete key is a key sequence which fully specifies one action
     to be performed by Emacs.  For example, `X' and `C-f' and `C-x m'
     are complete keys.  Complete keys derive their meanings from being
     bound (q.v.) to commands (q.v.).  Thus, `X' is conventionally
     bound to a command to insert `X' in the buffer; `C-x m' is
     conventionally bound to a command to begin composing a mail
     message.  *Note Keys::.

Completion
     Completion is what Emacs does when it automatically fills out an
     abbreviation for a name into the entire name.  Completion is done
     for minibuffer (q.v.) arguments when the set of possible valid
     inputs is known; for example, on command names, buffer names, and
     file names.  Completion occurs when TAB, SPC or RET is typed.
     *Note Completion::.

Continuation Line
     When a line of text is longer than the width of the window, it
     takes up more than one screen line when displayed.  We say that the
     text line is continued, and all screen lines used for it after the
     first are called continuation lines.  *Note Continuation: Basic.

Control Character
     ASCII characters with octal codes 0 through 037, and also code
     0177, do not have graphic images assigned to them.  These are the
     Control characters.  To type a Control character, hold down the
     CTRL key and type the corresponding non-Control character.  RET,
     TAB, ESC, LFD and DEL are all control characters.  *Note User
     Input::.

     When you are using the X Window System, every non-control
     character has a corresponding control character variant.

Copyleft
     A copyleft is a notice giving the public legal permission to
     redistribute a program or other work of art.  Copylefts are used by
     left-wing programmers to give people equal rights, just as
     copyrights are used by right-wing programmers to gain power over
     other people.

     The particular form of copyleft used by the GNU project is called
     the GNU General Public License.  *Note Copying::.

Current Buffer
     The current buffer in Emacs is the Emacs buffer on which most
     editing commands operate.  You can select any Emacs buffer as the
     current one.  *Note Buffers::.

Current Line
     The line point is on (*note Point::.).

Current Paragraph
     The paragraph that point is in.  If point is between paragraphs,
     the current paragraph is the one that follows point.  *Note
     Paragraphs::.

Current Defun
     The defun (q.v.) that point is in.  If point is between defuns, the
     current defun is the one that follows point.  *Note Defuns::.

Cursor
     The cursor is the rectangle on the screen which indicates the
     position called point (q.v.) at which insertion and deletion takes
     place.  The cursor is on or under the character that follows
     point.  Often people speak of `the cursor' when, strictly
     speaking, they mean `point'.  *Note Cursor: Basic.

Customization
     Customization is making minor changes in the way Emacs works.  It
     is often done by setting variables (*note Variables::.) or by
     rebinding key sequences (*note Keymaps::.).

Default Argument
     The default for an argument is the value that will be assumed if
     you do not specify one.  When the minibuffer is used to read an
     argument, the default argument is used if you just type RET.
     *Note Minibuffer::.

Default Directory
     When you specify a file name that does not start with `/' or `~',
     it is interpreted relative to the current buffer's default
     directory.  *Note Default Directory: Minibuffer File.

Defun
     A defun is a list at the top level of parenthesis or bracket
     structure in a program.  It is so named because most such lists in
     Lisp programs are calls to the Lisp function `defun'.  *Note
     Defuns::.

DEL
     DEL is a character that runs the command to delete one character of
     text.  *Note DEL: Basic.

Deletion
     Deletion means erasing text without copying it into the kill ring
     (q.v.).  The alternative is killing (q.v.).  *Note Deletion:
     Killing.

Deletion of Files
     Deleting a file means erasing it from the file system.  *Note Misc
     File Ops::.

Deletion of Messages
     Deleting a message means flagging it to be eliminated from your
     mail file.  Until you expunge (q.v.) the Rmail file, you can still
     undelete the messages you have deleted.  *Note Rmail Deletion::.

Deletion of Windows
     Deleting a window means eliminating it from the screen.  Other
     windows expand to use up the space.  The deleted window can never
     come back, but no actual text is thereby lost.  *Note Windows::.

Directory
     File directories are named collections in the file system, within
     which you can place individual files or subdirectories.  *Note
     Directories::.

Dired
     Dired is the Emacs facility that displays the contents of a file
     directory and allows you to "edit the directory", performing
     operations on the files in the directory.  *Note Dired::.

Disabled Command
     A disabled command is one that you may not run without special
     confirmation.  The usual reason for disabling a command is that it
     is confusing for beginning users.  *Note Disabling::.

Down Event
     Short for `button down event'.

Drag Event
     A drag event is the kind of input event generated when you press a
     mouse button, move the mouse, and then release the button.  *Note
     Mouse Buttons::.

Dribble File
     A file into which Emacs writes all the characters that the user
     types on the keyboard.  Dribble files are used to make a record for
     debugging Emacs bugs.  Emacs does not make a dribble file unless
     you tell it to.  *Note Bugs::.

Echo Area
     The echo area is the bottom line of the screen, used for echoing
     the arguments to commands, for asking questions, and printing
     brief messages (including error messages).  The messages are
     stored in the buffer `*Messages*' so you can review them later.
     *Note Echo Area::.

Echoing
     Echoing is acknowledging the receipt of commands by displaying
     them (in the echo area).  Emacs never echoes single-character key
     sequences; longer key sequences echo only if you pause while
     typing them.

Error
     An error occurs when an Emacs command cannot execute in the current
     circumstances.  When an error occurs, execution of the command
     stops (unless the command has been programmed to do otherwise) and
     Emacs reports the error by printing an error message (q.v.).
     Type-ahead is discarded.  Then Emacs is ready to read another
     editing command.

Error Message
     An error message is a single line of output displayed by Emacs
     when the user asks for something impossible to do (such as,
     killing text forward when point is at the end of the buffer).
     They appear in the echo area, accompanied by a beep.

ESC
     ESC is a character used as a prefix for typing Meta characters on
     keyboards lacking a META key.  Unlike the META key (which, like
     the SHIFT key, is held down while another character is typed), the
     ESC key is pressed once and applies to the next character typed.

Expunging
     Expunging an Rmail file or Dired buffer means really discarding the
     messages or files you have previously flagged for deletion.

File Name
     A file name is a name that refers to a file.  File names may be
     relative or absolute; the meaning of a relative file name depends
     on the current directory, but an absolute file name refers to the
     same file regardless of which directory is current.  On GNU and
     Unix systems, an absolute file name starts with a slash (the root
     directory) or with `~/' or `~USER/' (a home directory).

     Some people use the term "pathname" for file names, but we do not;
     we use the word "path" only in the term "search path" (q.v.).

File Name Component
     A file name component names a file directly within a particular
     directory.  On GNU and Unix systems, a file name is a sequence of
     file name components, separated by slashes.  For example,
     `foo/bar' is a file name containing two components, `foo' and
     `bar'; it refers to the file named `bar' in the directory named
     `foo' in the current directory.

Fill Prefix
     The fill prefix is a string that should be expected at the
     beginning of each line when filling is done.  It is not regarded
     as part of the text to be filled.  *Note Filling::.

Filling
     Filling text means shifting text between consecutive lines so that
     all the lines are approximately the same length.  *Note Filling::.

Formatted Text
     Formatted text is text that displays with formatting information
     while you edit.  Formatting information includes fonts, colors,
     and specified margins.  *Note Formatted Text::.

Frame
     A frame is a rectangular cluster of Emacs windows.  Emacs starts
     out with one frame, but you can create more.  You can subdivide
     each frame into Emacs windows (q.v.).  When you are using X
     windows, all the frames can be visible at the same time.  *Note
     Frames::.

Function Key
     A function key is a key on the keyboard that sends input but does
     not correspond to any character.  *Note Function Keys::.

Global
     Global means `independent of the current environment; in effect
     throughout Emacs'.  It is the opposite of local (q.v.).  Particular
     examples of the use of `global' appear below.

Global Abbrev
     A global definition of an abbrev (q.v.) is effective in all major
     modes that do not have local (q.v.) definitions for the same
     abbrev.  *Note Abbrevs::.

Global Keymap
     The global keymap (q.v.) contains key bindings that are in effect
     except when overridden by local key bindings in a major mode's
     local keymap (q.v.).  *Note Keymaps::.

Global Mark Ring
     The global mark ring records the series of buffers you have
     recently set a mark in.  In many cases you can use this to
     backtrack through buffers you have been editing in, or in which
     you have found tags.  *Note Global Mark Ring::.

Global Substitution
     Global substitution means replacing each occurrence of one string
     by another string through a large amount of text.  *Note Replace::.

Global Variable
     The global value of a variable (q.v.) takes effect in all buffers
     that do not have their own local (q.v.) values for the variable.
     *Note Variables::.

Graphic Character
     Graphic characters are those assigned pictorial images rather than
     just names.  All the non-Meta (q.v.) characters except for the
     Control (q.v.) characters are graphic characters.  These include
     letters, digits, punctuation, and spaces; they do not include RET
     or ESC.  In Emacs, typing a graphic character inserts that
     character (in ordinary editing modes).  *Note Basic Editing: Basic.

Highlighting
     Highlighting text means displaying it with a different foreground
     and/or background color to make it stand out from the rest of the
     text in the buffer.

Hardcopy
     Hardcopy means printed output.  Emacs has commands for making
     printed listings of text in Emacs buffers.  *Note Hardcopy::.

HELP
     You can type HELP at any time to ask what options you have, or to
     ask what any command does.  The character HELP is really `C-h'.
     *Note Help::.

Hyper
     Hyper is the name of a modifier bit which a keyboard input
     character may have.  To make a character Hyper, type it while
     holding down the HYPER key.  Such characters are given names that
     start with `Hyper-' (usually written `H-' for short).  *Note
     Hyper: User Input.

Inbox
     An inbox is a file in which mail is delivered by the operating
     system.  Rmail transfers mail from inboxes to Rmail files (q.v.)
     in which the mail is then stored permanently or until explicitly
     deleted.  *Note Rmail Inbox::.

Indentation
     Indentation means blank space at the beginning of a line.  Most
     programming languages have conventions for using indentation to
     illuminate the structure of the program, and Emacs has special
     commands to adjust indentation.  *Note Indentation::.

Indirect Buffer
     An indirect buffer is a buffer that shares the text of another
     buffer, called its base buffer.  *Note Indirect Buffers::.

Input Event
     An input event represents, within Emacs, one action taken by the
     user on the terminal.  Input events include typing characters,
     typing function keys, pressing or releasing mouse buttons, and
     switching between Emacs frames.  *Note User Input::.

Insertion
     Insertion means copying text into the buffer, either from the
     keyboard or from some other place in Emacs.

Justification
     Justification means adding extra spaces to lines of text to make
     them come exactly to a specified width.  *Note Justification:
     Filling.

Keyboard Macro
     Keyboard macros are a way of defining new Emacs commands from
     sequences of existing ones, with no need to write a Lisp program.
     *Note Keyboard Macros::.

Key Sequence
     A key sequence (key, for short) is a sequence of input events
     (q.v.) that are meaningful as a single unit.  If the key sequence
     is enough to specify one action, it is a complete key (q.v.); if
     it is not enough, it is a prefix key (q.v.).  *Note Keys::.

Keymap
     The keymap is the data structure that records the bindings (q.v.)
     of key sequences to the commands that they run.  For example, the
     global keymap binds the character `C-n' to the command function
     `next-line'.  *Note Keymaps::.

Keyboard Translation Table
     The keyboard translation table is an array that translates the
     character codes that come from the terminal into the character
     codes that make up key sequences.  *Note Keyboard Translations::.

Kill Ring
     The kill ring is where all text you have killed recently is saved.
     You can reinsert any of the killed text still in the ring; this is
     called yanking (q.v.).  *Note Yanking::.

Killing
     Killing means erasing text and saving it on the kill ring so it
     can be yanked (q.v.) later.  Some other systems call this
     "cutting".  Most Emacs commands to erase text do killing, as
     opposed to deletion (q.v.).  *Note Killing::.

Killing Jobs
     Killing a job (such as, an invocation of Emacs) means making it
     cease to exist.  Any data within it, if not saved in a file, is
     lost.  *Note Exiting::.

List
     A list is, approximately, a text string beginning with an open
     parenthesis and ending with the matching close parenthesis.  In C
     mode and other non-Lisp modes, groupings surrounded by other kinds
     of matched delimiters appropriate to the language, such as braces,
     are also considered lists.  Emacs has special commands for many
     operations on lists.  *Note Lists::.

Local
     Local means `in effect only in a particular context'; the relevant
     kind of context is a particular function execution, a particular
     buffer, or a particular major mode.  It is the opposite of `global'
     (q.v.).  Specific uses of `local' in Emacs terminology appear
     below.

Local Abbrev
     A local abbrev definition is effective only if a particular major
     mode is selected.  In that major mode, it overrides any global
     definition for the same abbrev.  *Note Abbrevs::.

Local Keymap
     A local keymap is used in a particular major mode; the key bindings
     (q.v.) in the current local keymap override global bindings of the
     same key sequences.  *Note Keymaps::.

Local Variable
     A local value of a variable (q.v.) applies to only one buffer.
     *Note Locals::.

`M-'
     `M-' in the name of a character is an abbreviation for META, one
     of the modifier keys that can accompany any character.  *Note User
     Input::.

`M-C-'
     `M-C-' in the name of a character is an abbreviation for
     Control-Meta; it means the same thing as `C-M-'.  If your terminal
     lacks a real META key, you type a Control-Meta character by typing
     ESC and then typing the corresponding Control character.  *Note
     C-M-: User Input.

`M-x'
     `M-x' is the key sequence which is used to call an Emacs command by
     name.  This is how you run commands that are not bound to key
     sequences.  *Note M-x::.

Mail
     Mail means messages sent from one user to another through the
     computer system, to be read at the recipient's convenience.  Emacs
     has commands for composing and sending mail, and for reading and
     editing the mail you have received.  *Note Sending Mail::.  *Note
     Rmail::, for how to read mail.

Major Mode
     The Emacs major modes are a mutually exclusive set of options,
     each of which configures Emacs for editing a certain sort of text.
     Ideally, each programming language has its own major mode.  *Note
     Major Modes::.

Mark
     The mark points to a position in the text.  It specifies one end
     of the region (q.v.), point being the other end.  Many commands
     operate on all the text from point to the mark.  Each buffer has
     its own mark.  *Note Mark::.

Mark Ring
     The mark ring is used to hold several recent previous locations of
     the mark, just in case you want to move back to them.  Each buffer
     has its own mark ring; in addition, there is a single global mark
     ring (q.v.).  *Note Mark Ring::.

Menu Bar
     The menu bar is the line at the top of an Emacs frame.  It contains
     words you can click on with the mouse to bring up menus.  The menu
     bar feature is supported only with X.  *Note Menu Bars::.

Message
     See `mail'.

Meta
     Meta is the name of a modifier bit which a command character may
     have.  It is present in a character if the character is typed with
     the META key held down.  Such characters are given names that start
     with `Meta-' (usually written `M-' for short).  For example, `M-<'
     is typed by holding down META and at the same time typing `<'
     (which itself is done, on most terminals, by holding down SHIFT
     and typing `,').  *Note Meta: User Input.

Meta Character
     A Meta character is one whose character code includes the Meta bit.

Minibuffer
     The minibuffer is the window that appears when necessary inside the
     echo area (q.v.), used for reading arguments to commands.  *Note
     Minibuffer::.

Minibuffer History
     The minibuffer history records the text you have specified in the
     past for minibuffer arguments, so you can conveniently use the
     same text again.  *Note Minibuffer History::.

Minor Mode
     A minor mode is an optional feature of Emacs which can be switched
     on or off independently of all other features.  Each minor mode
     has a command to turn it on or off.  *Note Minor Modes::.

Minor Mode Keymap
     A keymap that belongs to a minor mode and is active when that mode
     is enabled.  Minor mode keymaps take precedence over the buffer's
     local keymap, just as the local keymap takes precedence over the
     global keymap.  *Note Keymaps::.

Mode Line
     The mode line is the line at the bottom of each window (q.v.),
     giving status information on the buffer displayed in that window.
     *Note Mode Line::.

Modified Buffer
     A buffer (q.v.) is modified if its text has been changed since the
     last time the buffer was saved (or since when it was created, if it
     has never been saved).  *Note Saving::.

Moving Text
     Moving text means erasing it from one place and inserting it in
     another.  The usual way to move text by killing (q.v.) and then
     yanking (q.v.).  *Note Killing::.

Named Mark
     A named mark is a register (q.v.) in its role of recording a
     location in text so that you can move point to that location.
     *Note Registers::.

Narrowing
     Narrowing means creating a restriction (q.v.) that limits editing
     in the current buffer to only a part of the text in the buffer.
     Text outside that part is inaccessible to the user until the
     boundaries are widened again, but it is still there, and saving
     the file saves it all.  *Note Narrowing::.

Newline
     Linefeed characters in the buffer terminate lines of text and are
     therefore also called newlines.  *Note Newline: Text Characters.

Numeric Argument
     A numeric argument is a number, specified before a command, to
     change the effect of the command.  Often the numeric argument
     serves as a repeat count.  *Note Arguments::.

Overwrite Mode
     Overwrite mode is a minor mode.  When it is enabled, ordinary text
     characters replace the existing text after point rather than
     pushing it to the right.  *Note Minor Modes::.

Page
     A page is a unit of text, delimited by formfeed characters (ASCII
     control-L, code 014) coming at the beginning of a line.  Some Emacs
     commands are provided for moving over and operating on pages.
     *Note Pages::.

Paragraph
     Paragraphs are the medium-size unit of English text.  There are
     special Emacs commands for moving over and operating on paragraphs.
     *Note Paragraphs::.

Parsing
     We say that certain Emacs commands parse words or expressions in
     the text being edited.  Really, all they know how to do is find
     the other end of a word or expression.  *Note Syntax::.

Point
     Point is the place in the buffer at which insertion and deletion
     occur.  Point is considered to be between two characters, not at
     one character.  The terminal's cursor (q.v.) indicates the
     location of point.  *Note Point: Basic.

Prefix Argument
     See `numeric argument'.

Prefix Key
     A prefix key is a key sequence (q.v.) whose sole function is to
     introduce a set of longer key sequences.  `C-x' is an example of
     prefix key; any two-character sequence starting with `C-x' is
     therefore a legitimate key sequence.  *Note Keys::.

Primary Rmail File
     Your primary Rmail file is the file named `RMAIL' in your home
     directory.  That's where Rmail stores your incoming mail, unless
     you specify a different file name.  *Note Rmail::.

Primary Selection
     The primary selection is one particular X selection (q.v.); it is
     the selection that most X applications use for transferring text
     to and from other applications.

     The Emacs kill commands set the primary selection and the yank
     command uses the primary selection when appropriate.  *Note
     Killing::.

Prompt
     A prompt is text printed to ask the user for input.  Displaying a
     prompt is called prompting.  Emacs prompts always appear in the
     echo area (q.v.).  One kind of prompting happens when the
     minibuffer is used to read an argument (*note Minibuffer::.); the
     echoing which happens when you pause in the middle of typing a
     multi-character key sequence is also a kind of prompting (*note
     Echo Area::.).

Quitting
     Quitting means canceling a partially typed command or a running
     command, using `C-g'.  *Note Quitting::.

Quoting
     Quoting means depriving a character of its usual special
     significance.  In Emacs this is usually done with `C-q'.  What
     constitutes special significance depends on the context and on
     convention.  For example, an "ordinary" character as an Emacs
     command inserts itself; so in this context, a special character is
     any character that does not normally insert itself (such as DEL,
     for example), and quoting it makes it insert itself as if it were
     not special.  Not all contexts allow quoting.  *Note Quoting:
     Basic.

Read-Only Buffer
     A read-only buffer is one whose text you are not allowed to change.
     Normally Emacs makes buffers read-only when they contain text which
     has a special significance to Emacs; for example, Dired buffers.
     Visiting a file that is write protected also makes a read-only
     buffer.  *Note Buffers::.

Rectangle
     A rectangle consists of the text in a given range of columns on a
     given range of lines.  Normally you specify a rectangle by putting
     point at one corner and putting the mark at the opposite corner.
     *Note Rectangles::.

Recursive Editing Level
     A recursive editing level is a state in which part of the
     execution of a command involves asking the user to edit some text.
     This text may or may not be the same as the text to which the
     command was applied.  The mode line indicates recursive editing
     levels with square brackets (`[' and `]').  *Note Recursive Edit::.

Redisplay
     Redisplay is the process of correcting the image on the screen to
     correspond to changes that have been made in the text being edited.
     *Note Redisplay: Screen.

Regexp
     See `regular expression'.

Region
     The region is the text between point (q.v.) and the mark (q.v.).
     Many commands operate on the text of the region.  *Note Region:
     Mark.

Registers
     Registers are named slots in which text or buffer positions or
     rectangles can be saved for later use.  *Note Registers::.

Regular Expression
     A regular expression is a pattern that can match various text
     strings; for example, `l[0-9]+' matches `l' followed by one or more
     digits.  *Note Regexps::.

Repeat Count
     See `numeric argument'.

Replacement
     See `global substitution'.

Restriction
     A buffer's restriction is the amount of text, at the beginning or
     the end of the buffer, that is temporarily inaccessible.  Giving a
     buffer a nonzero amount of restriction is called narrowing (q.v.).
     *Note Narrowing::.

RET
     RET is a character that in Emacs runs the command to insert a
     newline into the text.  It is also used to terminate most arguments
     read in the minibuffer (q.v.).  *Note Return: User Input.

Rmail File
     An Rmail file is a file containing text in a special format used by
     Rmail for storing mail.  *Note Rmail::.

Saving
     Saving a buffer means copying its text into the file that was
     visited (q.v.) in that buffer.  This is the way text in files
     actually gets changed by your Emacs editing.  *Note Saving::.

Scroll Bar
     A scroll bar is a tall thin hollow box that appears at the side of
     a window.  You can use mouse commands in the scroll bar to scroll
     the window.  The scroll bar feature is supported only with X.
     *Note Scroll Bars::.

Scrolling
     Scrolling means shifting the text in the Emacs window so as to see
     a different part of the buffer.  *Note Scrolling: Display.

Searching
     Searching means moving point to the next occurrence of a specified
     string or the next match for a specified regular expression.
     *Note Search::.

Search Path
     A search path is a list of directory names, to be used for
     searching for files for certain purposes.  For example, the
     variable `load-path' holds a search path for finding Lisp library
     files.  *Note Lisp Libraries::.

Secondary Selection
     The secondary selection is one particular X selection; some X
     applications can use it for transferring text to and from other
     applications.  Emacs has special mouse commands for transferring
     text using the secondary selection.  *Note Secondary Selection::.

Selecting
     Selecting a buffer means making it the current (q.v.) buffer.
     *Note Selecting: Buffers.

Selection
     The X window system allows an application program to specify named
     selections whose values are text.  A program can also read the
     selections that other programs have set up.  This is the principal
     way of transferring text between window applications.  Emacs has
     commands to work with the primary (q.v.) selection and the
     secondary (q.v.) selection.

Self-Documentation
     Self-documentation is the feature of Emacs which can tell you what
     any command does, or give you a list of all commands related to a
     topic you specify.  You ask for self-documentation with the help
     character, `C-h'.  *Note Help::.

Sentences
     Emacs has commands for moving by or killing by sentences.  *Note
     Sentences::.

Sexp
     A sexp (short for `s-expression') is the basic syntactic unit of
     Lisp in its textual form: either a list, or Lisp atom.  Many Emacs
     commands operate on sexps.  The term `sexp' is generalized to
     languages other than Lisp, to mean a syntactically recognizable
     expression.  *Note Sexps: Lists.

Simultaneous Editing
     Simultaneous editing means two users modifying the same file at
     once.  Simultaneous editing if not detected can cause one user to
     lose his work.  Emacs detects all cases of simultaneous editing
     and warns one of the users to investigate.  *Note Simultaneous
     Editing: Interlocking.

String
     A string is a kind of Lisp data object which contains a sequence of
     characters.  Many Emacs variables are intended to have strings as
     values.  The Lisp syntax for a string consists of the characters
     in the string with a `"' before and another `"' after.  A `"' that
     is part of the string must be written as `\"' and a `\' that is
     part of the string must be written as `\\'.  All other characters,
     including newline, can be included just by writing them inside the
     string; however, backslash sequences as in C, such as `\n' for
     newline or `\241' using an octal character code, are allowed as
     well.

String Substitution
     See `global substitution'.

Syntax Table
     The syntax table tells Emacs which characters are part of a word,
     which characters balance each other like parentheses, etc.  *Note
     Syntax::.

Super
     Super is the name of a modifier bit which a keyboard input
     character may have.  To make a character Super, type it while
     holding down the SUPER key.  Such characters are given names that
     start with `Super-' (usually written `s-' for short).  *Note
     Super: User Input.

Tags Table
     A tags table is a file that serves as an index to the function
     definitions in one or more other files.  *Note Tags::.

Termscript File
     A termscript file contains a record of all characters sent by
     Emacs to the terminal.  It is used for tracking down bugs in Emacs
     redisplay.  Emacs does not make a termscript file unless you tell
     it to.  *Note Bugs::.

Text
     Two meanings (*note Text::.):

        * Data consisting of a sequence of characters, as opposed to
          binary numbers, images, graphics commands, executable
          programs, and the like.  The contents of an Emacs buffer are
          always text in this sense.

        * Data consisting of written human language, as opposed to
          programs, or following the stylistic conventions of human
          language.

Top Level
     Top level is the normal state of Emacs, in which you are editing
     the text of the file you have visited.  You are at top level
     whenever you are not in a recursive editing level (q.v.) or the
     minibuffer (q.v.), and not in the middle of a command.  You can
     get back to top level by aborting (q.v.) and quitting (q.v.).
     *Note Quitting::.

Transposition
     Transposing two units of text means putting each one into the place
     formerly occupied by the other.  There are Emacs commands to
     transpose two adjacent characters, words, sexps (q.v.) or lines
     (*note Transpose::.).

Truncation
     Truncating text lines in the display means leaving out any text on
     a line that does not fit within the right margin of the window
     displaying it.  See also `continuation line'.  *Note Truncation:
     Basic.

Undoing
     Undoing means making your previous editing go in reverse, bringing
     back the text that existed earlier in the editing session.  *Note
     Undo::.

User Option
     A user option is a variable (q.v.) that exists so that you can
     customize Emacs by setting it to a new value.  *Note Variables::.

Variable
     A variable is an object in Lisp that can store an arbitrary value.
     Emacs uses some variables for internal purposes, and has others
     (known as `user options' (q.v.)) just so that you can set their
     values to control the behavior of Emacs.  The variables used in
     Emacs that you are likely to be interested in are listed in the
     Variables Index in this manual.  *Note Variables::, for
     information on variables.

Version Control
     Version control systems keep track of multiple versions of a
     source file.  They provide a more powerful alternative to keeping
     backup files (q.v.).  *Note Version Control::.

Visiting
     Visiting a file means loading its contents into a buffer (q.v.)
     where they can be edited.  *Note Visiting::.

Whitespace
     Whitespace is any run of consecutive formatting characters (space,
     tab, newline, and backspace).

Widening
     Widening is removing any restriction (q.v.) on the current buffer;
     it is the opposite of narrowing (q.v.).  *Note Narrowing::.

Window
     Emacs divides a frame (q.v.) into one or more windows, each of
     which can display the contents of one buffer (q.v.) at any time.
     *Note Screen::, for basic information on how Emacs uses the screen.
     *Note Windows::, for commands to control the use of windows.

Word Abbrev
     Synonymous with `abbrev'.

Word Search
     Word search is searching for a sequence of words, considering the
     punctuation between them as insignificant.  *Note Word Search::.

WYSIWYG
     WYSIWYG stands for "What you see is what you get."  Emacs generally
     provides WYSIWYG editing for files of characters; in Enriched mode
     (*note Formatted Text::.), it provides WYSIWYG editing for files
     that include text formatting information.

Yanking
     Yanking means reinserting text previously killed.  It can be used
     to undo a mistaken kill, or for copying or moving text.  Some other
     systems call this "pasting".  *Note Yanking::.

