By "processing" we mean technical operations that are necessary to prepare library materials for access and use. So, centralized processing would mean undertaking of those operations by a central agency or body. Wynar says that "the term Centralized Processing may be broadly defined as any consolidated effort to bring under one control the technical operations necessary to prepare library materials for access and use at different service points".
Technical processing centres can be of different varieties. Broadly speaking, these can be: