DOCUMENT DELIVERY SERVICE .WORLD SCENARIO:
Earlier libraries and information centres had no capability to deliver the documents other than to buy them from the publishers, display them on the shelves and loan them when demanded by the users. In case, the document was not available with them, then borrow it from other libraries on inter-library loan and lend it to users for a specified period of time. With the introduction of xerography in mid-I950s and large scale use of photocopiers in libraries by 1970y, the DDS was not just confined to lending or interlending of documents, but also documents could be duplicated and permanently supplied to the users.
The libraries started using photocopiers for the supply of copies of documents, particularly of journal articles and parts of books. Most of the libraries still prefer supplying copies of the documents rather than the originals, so that the original may always remain in the library and not get damaged with excessive use. The advent of computers, scanners and telecommunication technologies in 1980s made it possible to store the documents in electronic form and transfer the same electronically to long distances via telecommunication networks almost instantly. Now, many libraries and information centres are using this technology for the delivery of documents to the intended users. This has greatly improved the speed of the service.