HTTP (HyperText Transfer Protocol) is the foundation of data communication on the World Wide Web. Designed by Tim Berners-Lee at CERN in 1989–1991, HTTP defines how messages are formatted and transmitted, and how web servers and browsers should respond to various commands.
Origins
When Tim Berners-Lee created the World Wide Web, he needed a protocol for clients (browsers) and servers to communicate. HTTP was designed to be simple and human-readable—a request-response protocol where clients ask for resources and servers provide them[1].
The first version, HTTP/0.9, was remarkably simple: a client sent a single line requesting a document, and the server returned the content. No headers, no metadata, no status codes—just the document itself.
How HTTP Works
HTTP follows a request-response model:
- Client sends request: Specifies a method (GET, POST, etc.), a URL, and optional headers
- Server processes request: Locates the resource and determines how to respond
- Server sends response: Returns a status code, headers, and the requested content
The protocol is stateless—each request is independent, with no memory of previous interactions. This simplicity made HTTP scalable to billions of users.
Evolution
HTTP has evolved to meet growing demands[2]:
- HTTP/0.9 (1991): Original single-line protocol
- HTTP/1.0 (1996): Added headers, status codes, and multiple content types
- HTTP/1.1 (1997): Persistent connections, chunked transfers, and caching
- HTTP/2 (2015): Binary protocol, multiplexing, and header compression
- HTTP/3 (2022): Built on QUIC for improved performance over unreliable networks
Key Concepts
Methods
HTTP defines several request methods:
- GET: Retrieve a resource (the most common method)
- POST: Submit data to be processed
- PUT: Replace a resource
- DELETE: Remove a resource
- HEAD: Retrieve headers only
Status Codes
Servers respond with three-digit status codes:
- 200 OK: Request succeeded
- 301 Moved Permanently: Resource has a new URL
- 404 Not Found: Resource doesn’t exist
- 500 Internal Server Error: Server failed to process the request
Impact
HTTP’s simplicity enabled the Web’s explosive growth. Unlike complex protocols designed by committee, HTTP was pragmatic—easy to implement, debug, and extend[3].
Today, HTTP carries not just web pages but APIs, streaming media, real-time communications, and virtually all modern internet applications. It has become the universal language of networked computing.
Sources
- Wikipedia. “HTTP.” Overview of HTTP’s history and technical details.
- MDN Web Docs. “Evolution of HTTP.” Documents the protocol’s development over time.
- IETF. “RFC 2616 - HTTP/1.1.” The formal HTTP/1.1 specification.