Proxy servers are also known as proxies. These servers are used in home networks, corporate intranets or by Internet Service Providers (ISPs). Proxy servers behave as a connection between a client and a server through networking. Proxy servers are useful with web browser and servers by managing network protocols such as HTTP.

Proxy servers develop three main functions and characteristics in the same time. These functions are firewalling and filtering, connection sharing and caching.

These functions are very important for networks like corporate intranets and ISP networks. The proxy servers begin to be useful when there are many users on a LAN and there is a desperate need for data privacy.

The first function of proxy servers, firewalling and filtering is not as popular or important as the other two functions. Proxy servers are not frequently used as firewalls. Installing a proxy server is in most of the cases much more difficult than installing a regular firewall. The difference is also made by the difficulty of maintaining these proxy servers compared to maintaining ordinary firewalls. Another tough thing to do is to configure individually each application protocol such as HTTP, SMTP or SOCKS. If these steps are carefully followed, proxies might have better results than a regular firewall, improving the network security and performance.

It is also known that there is the possibility of deploying both firewalls and proxy servers to work in tandem. For that the network administrators have to install both applications on the same server.

Web proxy servers might help network administrators in baring access to illegal domains but in the same time to allow access to other sites. The differences between a proxy server and a firewall is made in the moment we agree that firewall has the possibility to filter the information by the port number or the network address while proxy servers can also filter through the application content inside the messages.

The second property of proxy servers is connection sharing. It is true that in the last period many software products were developed in order to help the network share but proxy servers are a more scalable and cost-effective alternative for internet access.

The last mentioned property is caching. This mean that the information obtained through these proxy servers, even if they are public, free or anonymous, will be stored in a so called database named cache. Each time the same information is required that information is being restored from the cache memory without a direct connection to the server. This is the most important function that will certainly lead to the improvement of the internet speed.