According to Project Gutenberg's Online version of Webster's Unabridged Dictionary, Proxy: An agent that has authority to act for another; Cache: a hiding place for concealing and preserving provisions which it is inconvenient to carry. Squid acts as an agent, accepting requests from clients (such as browsers) and passes them to the appropriate Internet server. It stores a copy of the returned data in an on-disk cache. The real benefit of Squid emerges when the same data is requested multiple times, since a copy of the on-disk data is returned to the client, speeding up Internet access and saving bandwidth. Small amounts of disk space can have a significant impact on bandwidth usage and browsing speed. (?costs?)
Internet Firewalls (which are used to protect company networks) often have a proxy component. What makes the Squid proxy different from a firewall proxy? Most firewall proxies do not store copies of the returned data, instead they re-fetch requested data from the remote Internet server each time. Squid differs from firewall proxies in other ways too: -Many protocols are supported (firewalls often have specific proxies for specific protocols: it's difficult to ensure code security of a large program) -Hierarchies of proxies, arranged in complex relationships are possible
