Intermediate servers that forward all requests and responses for a specific service (e.g. web access), and often perform caching as well. These are used for five main purposes:

(1) To cut down on total bandwidth and thus speed up the network overall

(2) To increase individual privacy

(3) To implement "censorware" such as Bess

(4) To get around "censorware"

(5) To log the activities of users