The difference between interlibrary loan and document delivery: interlibrary loan refers to returning the whole book or a copy of the book to other libraries; Document delivery refers to the delivery of periodical papers, dissertations, standard documents and other single documents that do not need to be returned. Expand the difference between interlibrary loan and document delivery: document delivery refers to the delivery of periodical papers, dissertations, standard documents and other single documents that do not need to be returned; Interlibrary loan refers to the return of a whole book or a copy of a book to other libraries. Interlibrary loan service provides readers with the service of copying and transmitting original documents to domestic university libraries or document providers. Document delivery service refers to a service in which information providers, such as libraries or commercial service units, directly or indirectly deliver the required documents or other supplies to users in an effective way or at a reasonable cost for specific published or unpublished documents at the request of users.