The ultimate objective of any documentation or information activity is to provide the user with the information he needs, to the extent he requires, within a reasonable timeand cost frame. Let us now examine all these elements involved in information retrieval, and what literature search is all about. The user could be a layman who needs information to satisfy his curiosity, a student who needs more details than what is provided by the text book, a technical worker needing information to perform a certain task (e.g., a new welding process or a special distillation or purification technique), a research worker embarking on a new area of research, a product manager contemplating a new product line, or an administrator who has/to give his decision on anew project report or formulate a new strategy. Obviously, the nature and extent of information required by each, of them are different. Moreover, the urgency for getting information varies in different circumstances. While some of the needs of most of the users can be satisfied by the routine reference service provided by a good library, the needs of some others, especially research workers and project managers, can be satisfied only by extensive literature search entailing the use of several resources of a modem information centre and the skill and ingenuity of the information scientists.