You can use a proxy server for loads of different reasons. Many uses are focussed on security but they are also used for load balancing, caching data, controlling bandwidth requirements and censorship. Many proxies just are used to filter out nasty objects contained in web sites – perhaps cookies, advertisements and dodgy Active X controls and Java applets.
Here’s some of the more well known form of proxies –
Web Proxy Servers – are normally powered by som software which is run on a server. You may have heard of some of them like Glype and CGIProxy. They function primarily through a web browser and require no software to be installed on the client. The problem is that many of these are not that great at working with complicated web pages containing varied content. There’s better information to be found here – web proxy servers.
Open proxies are normally HTTP or SOCKS proxies which are literally all over the internet. These work very well with almost all clients and web pages because they do not need to modify pages to work. Unfortunately the majority of these open proxies are either hacked or misconfigured servers left open to be used. they represent a huge security risk for the users as many will store and forward personal details, install viruses or just leave your information logged.
Proxy networks are designed to offer a higher level of security by using something called onion routing. There are quite a few of these networks such as TOR, JAP or Freenet. They operate on a Peer to Peer basis and utilise members servers and PCs to create and operate the network. Again there can be a security risk with these because of malicious individuals operating rogue nodes in these networks designed to steal data and details.