The Service Bureau takes your work in electronic form and then produces high quality originals from that. In some cases the print shop and service bureau are part of the same company. Often though they are completely separate. For simple jobs the originals may be on photographic paper. Color work usually requires film which is slightly more expensive. The service bureau can usually provide color proofs of your job if you need it. Often a bureau offers a range of other functions such as high-quality scanning of photographs.