Before 1970, if you wanted to find a book in the library, you had to use the card catalog. This was arranged by either author or subject and employed the Dewey Decimal system which assigns a number to a book that is then stored on a book shelf in Dewey Decimal order. Then, in the early seventies, with the introduction of relatively cheap computers and time-share computing, searching for a book in the library meant sitting at a CRT or monitor, entering your search criteria, and pressing a button. Cataloging books was no longer done manually, writing up a card and putting it in its proper place in a wooden catalog drawer. Instead, library cataloging required a data entry operator to enter the specifics of the book, still controlled by a competent librarian, into the computer where the information was stored on hard disks. Library science became library information science.
Library automation made it possible for seekers to use other criteria to search for a book, besides the standards of author name or book title. In these cases, if you didn't know either, you had to query the librarian and had to have a pretty good idea what the book was about, some hint of who wrote it, and some idea of when it was published. With library automation, the criteria you can use to search for a book was extended. The power of information systems allows you to obtain a list of matching or nearly matching books, titles, authors, subjects, even lists of books by publishes for a given year. Now you can search by region, by country, by approximate dates of publication, by partial titles, partial author names, even by phrases that may appear in the book's jacket or synopsis. Library automation makes the library a more user friendly tool for researchers and students alike.
At first, library automation's benefits were available only locally, for a given library or a set of closely housed libraries. Then, in the 1980s and 1990s, the computer revolution revolved again, rendering systems of intercommunicating computers. A state library located at its capital, for instance, would have its holdings cataloged on a central computer. A parish our county library might also have its holding cataloged on its own central computer. Until these two computers could share information, neither knew what the other had, but once intercommunicating computers took hold, the library at the capital could find books held by the library at the county and similarly, the county library could find books held at the capital library. Libraries could form federations using library automation, extending their offerings to their patrons such that thousands of books that were not available on site could be ordered from another library hundreds of miles away.
Library automation has had a tremendous impact on the availability of knowledge to the common man. Today, library science is more appropriately called library information science, resting as it does on the marvels of telecommunication and client-server computing. Today, you can expect to find any book you want at your local library or, thanks to computers, another associated library that will get that book to you in a matter of days. Knowledge is universal.