Other applications besides Web browsers might need to use the proxy server functionality. In some cases, you might need to actually load client software. In essence, this client software modifies elements of the TCP/IP software on the system, to either make it aware of or enable it to cope with the existence of a proxy server. The good news is that the use of proxy servers is now so widespread that applications requiring special client software are becoming increasingly rare.
When Two Become One
By now, you might have realized that both firewalls and proxy servers play an important part in the network infrastructure. For that reason, many applications are now available that combine the functionality of both roles. These firewalling proxy servers provide a convenient means for an organization to control and secure the access of its network, and at the same time provide the benefits of Internet access to users.