Editing Proxy server (section)

{{short description|Computer server that makes and receives requests on behalf of a user}}
{{for|Wikipedia's policy on editing from open proxies|Wikipedia:Open proxies|selfref=y}}
{{other uses|Proxy (disambiguation)}}
{{Use dmy dates|date=April 2020}}

[[File:Proxy concept en.svg|thumb|upright=1.3|alt=Two computers connected via a proxy server. The first computer says to the proxy server: "ask the second computer what the time is".|Communication between two computers connected through a third computer acting as a proxy server. This can protect Alice's privacy, as Bob only knows about the proxy and cannot identify or contact Alice directly.]]

In [[computer networking]], a '''proxy server''' is a [[server application]] that acts as an [[intermediary]] between a [[client (computing)|client]] requesting a [[Web resource|resource]] and the server providing that resource.<ref>{{cite web |url=http://courses.cs.vt.edu/~cs4244/spring.09/documents/Proxies.pdf |title=World-Wide Web Proxies |first1=Ari |last1=Luotonen |author-link1=Ari Luotonen |first2=Kevin |last2=Altis |date=April 1994 |archive-url=https://web.archive.org/web/20161009061935/http://courses.cs.vt.edu/~cs4244/spring.09/documents/Proxies.pdf |archive-date=9 October 2016 |url-status=live}}</ref> It improves privacy, security, and possibly performance in the process.

Instead of connecting directly to a server that can fulfill a request for a resource, such as a file or [[web page]], the client directs the request to the proxy server, which evaluates the request and performs the required network transactions. This serves as a method to simplify or control the complexity of the request, or provide additional benefits such as [[load balancing (computing)|load balancing]], privacy, or security. Proxies were devised to add structure and [[Encapsulation (networking)|encapsulation]] to [[Distributed computing|distributed systems]].<ref>{{cite conference |last=Shapiro |first=Marc |date=May 1986 |title=Structure and Encapsulation in Distributed Systems: the Proxy Principle |url=https://hal.inria.fr/inria-00444651/document |conference=6th International Conference on Distributed Computing Systems |location=Cambridge, MA, USA |pages=198–204 |id=inria-00444651 |archive-url=https://web.archive.org/web/20181226233042/https://hal.inria.fr/inria-00444651/document |archive-date=26 December 2018 |access-date=26 December 2018 |url-status=live}}ccç÷</ref> A proxy server thus functions on behalf of the client when requesting service, potentially masking the true origin of the request to the resource server.