What Is a Proxy Server (Simple Explanation)

A proxy server sits between a client (a browser, an app, a script) and a destination server. The client talks to the proxy; the proxy talks to the destination. From the destination's perspective, the request came from the proxy, not the original client.

Forward proxy vs reverse proxy

A forward proxy sits in front of clients. A corporate network might route all employee web traffic through a forward proxy for content filtering. A reverse proxy sits in front of servers. Websites use reverse proxies for load balancing, caching, and security filtering.

What proxies are used for

• Anonymity: hide the client's IP address from the destination.
• Caching: store responses so repeated requests don't hit origin.
• Filtering: block certain destinations or content types.
• Load balancing: distribute requests across multiple backend servers.
• Security: inspect and filter traffic for threats before it reaches origin.