The HTTP Protocol Inside Out

Break down the structure of an HTTP request and response, including the start-line, headers, and body.

Explain the semantics of common HTTP methods (GET, POST, PUT, PATCH, DELETE) and when to use each.

Explain the semantic nuances of critical HTTP status codes, including caching (304), redirection (301 vs 302), and errors (4xx, 5xx).

Describe the purpose of key HTTP headers such as Content-Type, Authorization, and Accept.

Explain how HTTPS works at a high level, including the TLS handshake and certificate verification.

Compare HTTP/1.1, HTTP/2, and HTTP/3 in terms of connection handling and performance.

Explain what CORS is, why browsers enforce it, and how to configure it correctly on a backend.

Inspect and debug HTTP traffic using `curl` and browser developer tools.