Web-based proxies are programs that mediate between a workstation user in a networked environment and the Internet beyond. They are associated with a "gateway," which separates the internal network from the outside; a "firewall," which screens all incoming traffic and protects the network from unwelcome intruders; and a "caching" program, which looks locally for previously downloaded web pages. If the requested page is not found, the proxy server goes out to the Net and retrieves it, almost invisibly, for the user. Apparently, this is a safe, efficient way of handling inbound and outbound traffic on a network.