A proxy server is an application running on a computer that sits between a workstation user and a Web server, and it usually resides on the same network as its user. Proxy sites are often where you can locate these proxy servers.
A proxy server usually performs multiple roles: it always acts as a security and privacy mechanism, and its other functions are as a network management or a performance enhancement tool. If one or more Internet sites are frequently requested, these are likely to be in the proxy's cache, which will improve user response time. Proxies are also used as a sort of firewall, because it isolates you from connecting to the Internet. You can also obtain access to blocked websites and bypass work, school, college or company internet filters with the help of a proxy.
Another function of a proxy server is to carry out anonymous Web surfing. Using an anonymous web surfing proxy is advised, because surfing the web can be risky and your IP address causes you to expose some of your personal data to the rest of the world when you're surfing the net. Your browsing activity can be tracked, from the place of origin, to the type of browser you are currently using to explore the Web. When you visit this web page from a free web-based proxy you can have a completely different IP address. For example, you are currently browsing this web site using the IP address 121.96.233.170. As far as the Internet is concerned, the only IP address on the remote server(s) is the proxy's IP address. Only the proxy server knows the customer's IP address.
Searching for new fresh proxy servers is not difficult but most of the proxy sites online do not update their proxy list and most of the proxies are either dead, transparent, open or insecure. So you need to be careful when choosing a particular proxy website. Otherwise, using these sites could end up a huge tragedy for you.