Proxy Servers
Most server-based filtering is based on filters integrated into proxy
servers. Clients are directed through the proxy, either by explicitly
setting the browser to do so, or by transparent redirection. Each request
is checked, then fulfilled or redirected by the proxy server as appropriate.
Because proxies usually offer additional services, such as caching, there
are often additional benefits, including bandwidth savings, access
speedups, and tracking capabilities. Requests for inappropriate sites
can be redirected to more appropriate sites or to a page explaining
why the request was denied and offering suggestions for finding more
appropriate content.
Next: Label Servers