A Thin Client is an applet that implements client functionality in a client/server architecture. In the past, the term “Thin Client” had a close relationship to its size and complexity, but today the term Thin Client mostly refers to applets that can be executed without a formal installation process. The advantage of such applications is the ease of support from a central administrative source. For example, IT personnel no longer have to inquire about the version of software being executed, because a simple refresh will retrieve the latest copy from the web page. In sharp contrast, a Thick Client must be formally installed, and is not automatically downloaded.
See also: Applet, Client, Thick Client