HTTP - dejanu/linux GitHub Wiki

**Hypertext Transfer Protocol **

Connectionless and Stateless protocol build on top of TCP

Connectionless = the client makes a request and then disconnects from the server and when the response is ready the server re-establish the connection
Stateless = each request/response transaction is treated independently , cookies and sessions are used to track the state, clientul si server-ul stiu unul despre altul pe durata unui request?

base

---

HTTP message consist of one ore more headers, each on separate line, followed by a blank line.

HTTP methods:

1. GET

• retrieve resource from server;
• does not have a body;
• sends the parameters for the requested resource in the url
  eg URL: http://domain.com/search?name=ford&model=car
  eg REST url: http://domain.com/search/ford/car

2. POST

• create or update resource on server (mostly CREATE);
• the data is send in the body of the HTTP request;
• the parameters can be send in the url query and in the body of the HTTP request;
• "Resend or Leave Page" - browsers do not reissue POST request
• NON-IDEMPOTENT (creates the same resource multiple times, eg contact form)

• idempotent = HTTP method that can be called many times , and has the same outcome each time f(f(x)) = f(x)

3. PUT

• create or update resource on server (mostly UPDATE);
• IDEMPOTENT (always returns the same result)

4. PATH

• applies partial modification to the resource on the server (takes the fields you gave it and assumes that they are the one to change)
• NON-IDEMPOTENT