Indexing:

In libraries, the card catalog is the index. The three indices are used in the library. The Author, Subject and title are the 3 indices. Each index is relative. The index permits the user to find the book according to the feature of the book. Separately from the feature the indices also give the number or the position of the book.

To search for a book, we seem into any of the indices and find the number. With this number, we can locate the shelves containing books in the range of the number we are searching for. Subsequent to the particular shelf is located, following is the lexical order of the number, we locate the book.

Actually, the book is retrieved from the system of the storage. Theoretically, the book is found logically from the system of retrieval. The numbers and shelves are the storage system. The card indices are the recovery system. The books are acknowledged with one system and retrieved with the help of the other system. The customer specifies the book by using the retrieval system. The librarian recovers the book by using the storage system. The retrieval systems are also based on relative search. If the relative retrieval system remembers facts like

•  The program that formed the document
•  The type of document - whether the document is graphics or word
•  The program which last opened the document
•  If the document is remarkably large or small.
•  If the document has untouched for a long time
•  For how elongated the document was last open
•  The amount of information that was added or deleted through the last edit
•  Whether the document has edited by more than one type of program
•  Whether the document holds embedded objects from other programs
•  Whether the document was formed from scratch or cloned from the other
•  If the document is often edited
•  If the document is often viewed but rarely edited
•  Whether the document has printed and where
•  How frequently the document has been printed, and whether the changes were made to it each time instantly before printing
•  Whether the document has fixed and to whom
•  Whether the document has emailed and to whom