Uses of proxy browser-A proxy server acts as a security barrier between your internal network and the Internet, keeping others on the Internet from being able to obtain access to information that is located on your internal network

 1. Open Mozilla Firefox.

2. Click on Tools then click on Options.

3. Click on the Advance tab, then click on the Network sub-tab and finally on the Settings button.

4. Tick the Manual Proxy Configuration.

5. In the HTTP Proxy: box, type the IP address of the proxy server.

6. In the Port: box, type the in the port number that is used by the proxy server.

7. Click OK to close the Connection Settings window.

8. Click OK to close the Options window.

Just google you will find many proxy lsit of website.