A virtual library is an organized collection of resources stored in digital format which are accessible by computers. A virtual library exists in cyberspace only. There are no buildings or shelves. According to Gunn in Virtual Libraries Supporting Student Learning, 2000 the emphasis in virtual libraries is on organization and access, not on physical collections. The design determines the type of learning, for a particular community of users that the virtual library supports.
A virtual library, also known as a digital or electronic library may be defined as a system that is accessible from anywhere via the internet, to deliver knowledge directly to their users, without being confined to the contents of a physical library nor by being caught in a web of unorganized, unmanaged information. Information from any online source can be managed and shared by librarians with their users, making more knowledge available to users than ever before; the goal of an e-library is to perform online all the functions of the traditional library, plus many more available in today's digital world.(Deb,Kar, Setting Up an Electronic Library:the case of TERI,2005)
The Digital Library Federation(DLF)defines digital libraries as
"organizations that provide the resources, including the specialized staff, to select, structure, offer intellectual access to, interpret, distribute, preserve the integrity of, and ensure the persistence over time of collections of digital works so that they are readily and economically available for use by a defined community or set of communities."
There are numerous definitions of what is a virtual library. In research literature, the terms digital, electronic, e-libraries and virtual libraries are frequently interchangeable.