-Handles circulation activities including: lending, return, renewal, place on hold, etc.
-Manages library materials: circulation type, location, patron database, and other transactions such as fines, lost books, etc
-May have added features such as inventory, support for MARC, Z39.50 and ILL standards, etc.
-May support security systems that lets users self check books in or out of the library
-Functional modules - most systems offer the basic modules - cataloging, OPAC and circulation - in a library software package, and the other functions such as acquisition, serial control, interlibrary loan (ILL), and Web OPAC are usually provided as optional add on modules or part of a main module
-Operating systems - each system may work for a particular OS like Windows, Unix, or it may work for both Windows and Unix environment
-Database systems - major systems normally make use of DBMS offered by different vendors like Oracle, Informix, MS SQL, MS Access etc...
-Network architecture - major systems run on the client-server architecture and use TCP-IP to communicate across networks (LANs and WANs)
-User interface - the use of a graphical user interface (GUI) is the norm for current systems because users find it easier to work with and it allows a wide range of tasks to be accomplished with a click of a mouse
-Library automation standards - provisions for library industry standards such as MARC and Z39.50 are normally integrated in major systems