An HTTP proxy is an intermediary that receives web requests from a client, forwards them to a server, and returns the response. In simple form it can cache, filter, log, or rewrite traffic. In security tools, a proxy may also sit in the middle of encrypted sessions after the client trusts a local certificate, allowing inspection of HTTPS traffic.
That middle position makes proxies important in cyber security. Defenders use them to debug applications, analyze headers and cookies, test authentication flows, and spot risky data exposure. Attackers can abuse the same role to intercept credentials, modify requests, or hide malicious traffic behind a trusted endpoint. Because a proxy can see session tokens, internal URLs, and other sensitive artifacts, flaws in proxy software or weak certificate handling can expose data that was meant to stay private. For that reason, proxy updates and access controls deserve close attention.