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early 15c., proccy, prokecye, "agency of one who acts instead of another; letter of power of attorney," contraction of Anglo-French procuracie (c.1300), from Medieval Latin procuratia "administration," from Latin procuratio "a caring for, management," from procurare "manage" (see procure). Also cf. proctor (n.). Meaning "person who acts in place of another" is from 1610s.
A process that accepts requests for some service and passes them on to the real server. A proxy may run on dedicated hardware or may be purely software. It may transform the request in some way or provide some additional layer of functionality such as caching or remote access. A proxy may be intended to increase security, e.g. a web proxy that allows multiple clients inside an organisation to access the Internet through a single secure, shared connection.