A proxy server is an intermediary server through which other computers access the Internet. It serves as a gateway that can monitor and filter all traffic that passes through it. Businesses, universities, and other large organizations often use proxy servers on their networks to improve security and make it easier to manage network traffic.
When your computer uses a proxy server, it sends all Internet-bound traffic through the proxy server, which forwards it to the destination. Any response comes through that same proxy server, which sends it to your computer. There are several reasons that you or your organization may want to use a proxy server, and some of the most common reasons are listed below:
- Privacy: Computers requesting data through a proxy server will appear to the rest of the Internet using the proxy server's IP address instead of their own. Each request is anonymized, which makes it difficult for websites to track individual users and devices.
- Content filtering: A proxy server can analyze all incoming traffic and block certain websites and content. Many organizations block content that may be dangerous (like sites known to spread viruses) or workplace-inappropriate (like pornography) to keep the employees on their network safe.
- Caching: If the same website is requested multiple times by different devices, the proxy server can save it in its local data cache. It only needs to download data from the web server once before it can deliver it to everyone else from its cache — which is considerably faster than downloading it multiple times.
- Security: A proxy server may act as a firewall between an internal network and the Internet. It can inspect both incoming and outgoing network connections, blocking untrusted connections and allowing trusted ones through.
- Logging: Network administrators can access logs of incoming and outgoing data passing through the proxy server to monitor all network activity from one location.
- Geolocation: A proxy server set up to allow you to connect to it over the Internet can help mask your location. By connecting to a remote proxy server, you will appear to be in the proxy server's location instead of your own, which can help you access sites with location-restricted content.
Both proxy servers and Virtual Private Networks (VPNs) can act as intermediaries for network traffic, but they are not the same thing. A VPN connection is end-to-end encrypted, which prevents any other computers between the client and the VPN server from reading its traffic. A proxy server connection is not necessarily encrypted but instead focuses on other services, like content filtering and data caching.