HTTPviesti

HTTPviesti refers to the data exchanged between client and server in the Hypertext Transfer Protocol (HTTP). An HTTP message can be either a request sent by a client or a response returned by a server. The protocol defines a simple textual structure for headers and an optional body. In HTTP/1.1, messages are typically plain text with the body used for payloads such as HTML, JSON, or binary data.

A request message begins with a start line that includes the method (for example, GET, POST, PUT), the request-target (origin form or absolute form), and the HTTP version (such as HTTP/1.1). This is followed by header fields, each on its own line in the format name: value. A blank line separates headers from the body. If a body is sent, its size is indicated by Content-Length or it is transmitted using Transfer-Encoding. The Host header is mandatory in HTTP/1.1 to identify the target server.

A response message starts with a status line containing the HTTP version, a numeric status code, and a reason phrase. It is followed by headers and a blank line, then an optional body. Status codes indicate the result of the request (for example, 200 OK, 404 Not Found, 500 Internal Server Error).

Transport and evolution: HTTP/1.1 introduced persistent connections and more flexible headers. HTTP/2 and HTTP/3 use binary framing and multiplexing to improve performance, while all HTTP traffic can be secured with TLS to form HTTPS.

Common headers include Host, User-Agent, Accept, Content-Type, Content-Length, Cache-Control, and Connection. Transfer-Encoding: chunked enables streaming of large or unknown-length bodies. Understanding HTTP messages is essential for debugging, API design, and web development.