Editing Proxy server (section)

===Accessing services anonymously===
{{Main|Anonymizer}}
An anonymous proxy server (sometimes called a web proxy) generally attempts to anonymize web surfing. [[Anonymizer]]s may be differentiated into several varieties. The destination server (the server that ultimately satisfies the web request) receives requests from the anonymizing proxy server and thus does not receive information about the end user's address. The requests are not anonymous to the anonymizing proxy server, however, and so a degree of trust is present between the proxy server and the user. Many proxy servers are funded through a continued advertising link to the user.

'''Access control''': Some proxy servers implement a logon requirement. In large organizations, authorized users must log on to gain access to the [[World Wide Web|web]]. The organization can thereby track usage to individuals. Some anonymizing proxy servers may forward [[Network packet|data packets]] with header lines such as HTTP_VIA, HTTP_X_FORWARDED_FOR, or HTTP_FORWARDED, which may reveal the IP address of the client. Other anonymizing proxy servers, known as elite or high-anonymity proxies, make it appear that the proxy server is the client. A website could still suspect a proxy is being used if the client sends packets that include a cookie from a previous visit that did not use the high-anonymity proxy server. Clearing cookies, and possibly the cache, would solve this problem.

====QA geotargeted advertising====
Advertisers use proxy servers for validating, checking and quality assurance of [[geotargeting|geotargeted ads]]. A geotargeting ad server checks the request source IP address and uses a [[Internet geolocation|geo-IP database]] to determine the geographic source of requests.<ref>{{cite web|title=Hot Tactics For Geo-Targeted Ads on Google & Bing|date=October 2013|url=http://searchengineland.com/hot-tactics-for-geo-targeted-ads-on-google-bing-smx-east-173213|access-date=7 February 2014|archive-date=14 February 2014|archive-url=https://web.archive.org/web/20140214092544/http://searchengineland.com/hot-tactics-for-geo-targeted-ads-on-google-bing-smx-east-173213|url-status=live}}</ref> Using a proxy server that is physically located inside a specific country or a city gives advertisers the ability to test geotargeted ads.