HTTP Overview
HTTP is Stateless
Each requested resource is a separate, independent, request to the server -- it is a stateless protocol.
HTTP Versions
W3C and
Internet Engineering Task Force (IETF) oversees the Hypertext Transfer Protocol.
- HTTP 1.0 (1996)
- HTTP 1.1 (1999)
- HTTP 2 (2014)
An HTTP Conversation
- Client Request
- METHOD Resource HTTP Version
- Client Generated Headers
- Request Body
- Server Response
- Status Line
- Server Generated Headers
- Data
Common Headers
Request (Browser)
- Host
- User-Agent
- Referer
- Accept
- Accept-Language
- Accept-Encoding
- Accept-Charset
- Cookie
- If-Modified-Since
Response (Server)
- Last-Modified
- Content-Length
- Content-Type
- Connection
HTTP 1.1 Methods
- GET
- POST
- HEAD
- PUT
- DELETE
- TRACE
- OPTIONS
HTTP Response Codes
HTTP 1.1 status codes commonly seen
- 200 OK
- 301 Moved permanently
- 302 Moved temporarily
- 304 Not modified
- 401 Unauthorized
- 403 Forbidden
- 404 Not found
- 500 Internal server error
The complete list: