What Is a Proxy Server? | eHow

What Is a Proxy Server?Large websites and web-based
games must have a place to store their information (known as a server)
so that people can continuously access them. Sites like Ebay depend on
these servers to track and process sales that go on through their
website. However, some people choose not to connect directly to these
sites and choose to use proxy servers instead.


Servers

Servers are made out of a hardware and software combination. Some servers are used to run services like online sales. They are also used to act as database storage centers for corporations and companies. Almost any personal computer can act as a server, depending on the size of the information stored and the amount of bandwidth the computer can handle. However, dedicated servers usually have faster CPUs and larger hard drives.



Proxy Servers
A proxy server acts as a medium between people who request server access (known as clients) and the server. A client would request access. The request would go to the proxy server, which would determine whether access could be granted according to its filters. For example, a proxy server may be set to deny requests from certain Internet Protocol (IP) addresses or regions. Proxy severs may also change the request's perceived qualifiers before asking for permission to access the server; or not even ask for permission.



Uses
A proxy server can be used to mask information client or the server itself, acting as another security barrier. This can prevent people from connecting directly to the server and performing malicious acts. It also can speed up access to the resources via web caching. Web caching by a proxy server reduces the bandwidth by keeping copies of documents passing through the server and returning the same information through the same path. Internet service providers usually use proxy servers for this reason.



Gateway Proxy Servers
Proxy servers can also be manipulated by clients to gain access. Some people create proxy servers to act as gateways to servers that usually use a combination of usernames, passwords and IP addresses to gain access. The proxy server can mask the IP address requesting access and instead change it to an accepted one.


Hostile Proxy Servers

Hostile proxy servers can be used as a spy tool. They are unknowingly placed between clients and the main server, monitoring and capturing data exchanges. It is suggested that people who exchange personal information online should only do so through a server with a Secure Socket Layer or SSL. The SSLs operate by cryptographically encoding the information and requiring a special digital certificate by both the user and the client.



By Paul Bright, eHow Contributor