File sharing allows users to access and share files over a network. It can be public or private and allows various levels of access like reading, writing, or modifying files. There are advantages like centralizing files for easy administration and updates, but also disadvantages like security problems, data redundancy, and lack of standardized structure. Different file sharing technologies include peer-to-peer networks with no central server, as well as instant messaging programs that allow file transfers between users. Common examples are AIM, ICQ, Windows Live Messenger, and Yahoo Messenger.