In client/server applications, a client designed to be especially small so that the bulk of the data processing occurs on the server. The term thin client is an especially popular buzzword now because it serves as a symbol dividing the computer industry into two camps. On one side is a group led by Netscape and Sun Microsystems advocating Java -based thin clients running on network computers. The other side, championed by Microsoft and Intel, is pushing ever-larger applications running locally on desktop computers.

Although the term thin client usually refers to software, it is increasingly used for computers, such as network computers and Net PCs, that are designed to serve as the clients for client/server architectures. A thin client is a network computer without a hard disk drive, whereas a fat client includes a disk drive.