What functions are performed by proxies?

Answer 1

A proxy server has a variety of potential purposes, including:

• To keep machines behind it anonymous, mainly for security.[1]
• To speed up access to resources (using caching). Web proxies are commonly used to cache web pages from a web server.[2]
• To prevent downloading the same content multiple times (and save bandwidth).
• To log / audit usage, e.g. to provide company employee internet usage reporting.
• To scan transmitted content for malware before delivery.
• To scan outbound content, e.g., for data loss prevention.
• Access enhancement/restriction
  • To apply access policy to network services or content, e.g. to block undesired sites.
  • To access sites prohibited or filtered by your ISP or institution.
  • To bypass security / parental controls.
  • To circumvent Internet filtering to access content otherwise blocked by governments.[3]
  • To allow a web site to make web requests to externally hosted resources (e.g. images, music files, etc.) when cross-domain restrictions prohibit the web site from linking directly to the outside domains.
  • To allow the browser to make web requests to externally hosted content on behalf of a website when cross-domain restrictions (in place to protect websites from the likes of data theft) prohibit the browser from directly accessing the outside domains).