HTTP

HTTP is based on the request-response communication model: 

• Client sends a request

• Server sends a response

• HTTP is a stateless protocol: where the protocol does not require the server to remember anything about the client between requests. 

Normally implemented over a TCP connection (80 is standard port number for HTTP) 

The following is the typical browser-server interaction using HTTP: 

1. User enters Web address in browser 

2. Browser uses DNS to locate IP address 

3. Browser opens TCP connection to server 

4. Browser sends HTTP request over connection

5. Server sends HTTP response to browser over connection 

6. Browser displays body of response in the client area of the browser window