A proxy site provides a way for you to browse the internet without being traced.  Many proxy sites have a search bar type feature that allows you to type in the web address, once you do this, the proxy site will automatically generate the site you wanted in its own server.  After that, you do not have to do anything else but simply browse the website as you would normally do without the proxy.

The functioning principle is simple: a web proxy is an intermediate between your computer and the site your are trying to access. When your computer requests a Web page, it is retrieved by the proxy server and then sent to your computer. The effect of this action is that the computer hosting the Web page never comes into direct contact with anything on your home network, other than the proxy server.

Happy Unblocking!