HTTP Headers

HTTP headers are key-value pairs sent in HTTP requests and responses to convey metadata about the data being transferred, such as content type, caching directives, authentication tokens, and client/server information. They are a fundamental part of the HTTP protocol, enabling communication between clients (e.g., browsers) and servers to control behavior, security, and data handling. Headers are categorized into request headers (sent by clients), response headers (sent by servers), and general headers (applicable to both).

Also known as: HTTP Headers, Request Headers, Response Headers, HTTP Metadata, Header Fields

Why learn HTTP Headers?

Developers should learn HTTP headers to build efficient, secure, and interoperable web applications, as headers are essential for tasks like API authentication (using Authorization headers), content negotiation (via Accept headers), caching optimization (with Cache-Control), and security enforcement (e.g., CORS headers). They are critical in web development, API design, and debugging network issues, with use cases ranging from setting cookies in responses to handling cross-origin requests in modern web apps.

Learning Resources

• docs: MDN Web Docs: HTTP Headers
• tutorial: HTTP Headers Explained (freeCodeCamp)
• video: HTTP Headers Crash Course (YouTube)
• book: HTTP: The Definitive Guide (Book)