HTTP
In plain terms
The protocol browsers and servers use to exchange web data.
Going deeper
HyperText Transfer Protocol defines how clients request and servers return web resources via methods, headers, and status codes. It's the web's core communication protocol.
Under the hood
Stateless request-response; HTTP/2 and HTTP/3 improved performance with multiplexing and QUIC.
Examples
GET/POST, web browsing, REST APIs, status codes, headers.
Think of it like...
Like the standard language of polite requests and replies between browser and server.