A proxy server is a kind of server (a computer that delivers or "serves" information to other computers). The proxy links the user (often the Web browser on your personal computer, or a computer in a network or group) and another main server. The proxy can store information, so that if more than one user requests the same data, it delivers it, eliminating the need to tie up the main server with duplicated requests. The proxy can also filter transmissions, and is often used in workplace networks to screen out unwanted communications. An open proxy will accept connections from any network address, acting as a blind intermediary to virtually anybody. On the Internet, an open proxy can allow various kinds of malware (viruses, etc.) to be transmitted.