What is a User-Agent?

• A. Identifies the client software making the request
• B. Benign response body
• C. DNS resolver
• D. Encryption method

Answer: (A)

In HTTP, a User-Agent is a header in requests that identifies the client software making the request. It carries a string that describes the browser or library (and often its version and the operating system), for example something like a browser user agent string. This helps servers tailor responses, perform content negotiation, and collect analytics or troubleshoot problems based on which client is talking to them. It’s part of the request headers, not the response body, and it has nothing to do with DNS resolution or encryption methods.