Jargon's related to HTTP protocol
- URL : Uniform Resource Locator
- URI : Uniform Resource Identifier
- URN : Uniform Resource Name
- HTTP headers : metadata [key-value sent along with request & response]
- Response header : came from server
- Request header : came from client
- Representation header : encoding / compression
- Payload header : sending data to client or server
HTTP methods
Basic sets of operations that can be used to interact with server.
- GET : retrieve resource
- HEAD : no message body (response header only)
- OPTIONS : what options are available
- TRACE : loop back test
- DELETE : Remove a resource
- PUT : replace a resource
- POST : interact with resource (mostly add)
- PATCH : change part of a resource
Idempotent v/s Non-idempotent
- GET, PUT, DELETE, HEAD are idempotent kinds of methods as they don't make any changes to the data on the server.
- PATCH, POST, TRACE are non-idempotent kinds as it create new resource inside the server.
HTTP status code
- 1XX : Informational
- 2XX : Success (
200: successful action ,201: successful creation ,204: no content but get success header) - 3XX : Redirection (
301: moved permanently,302: temporery redirect ,304: not modified resource) - 4XX : Client error (
400: bad request,401: unauthorized,403: forbidden,404: page not found,405: method not allowed,409: conflict,429: too many request) - 5XX : Server error (
500: internal server error,501: not implimented yet,502: bad gateway or invalid request,503: service unavialable or maintainance,504: gateway timeout)