HTTP

Hypertext Transfer Protocol

Hypertext Transfer Protocol abbreviated as HTTP is a protocol which contains a set of rules and convention for transmitting and exchanging files via the internet. It is coordinated by WWW ie. World Wide Web Consortium. File can be any file like text file, image files, query results, or anything else. HTTP is a request and response standard of a client and a server. The basic communication is followed by sending a request from the client side and getting a response from the client side. Here HTTP servers are the Web Servers.

How HTTP Works:

• An HTTP client opens a connection and sends a request message to an HTTP server.
• The server then returns a response message.
• The server closes the connection (making HTTP a stateless protocol.

Basic Structure of HTTP

Request message contains :

• Request line , example : GET /images/logo.gif HTTP/1.1, which requests a resource called /images/logo.gif from server
• Headers , example : Accept-Language: en
• An empty line
• An optional message body

There are eight Request methods:

• HEAD provide information about the request or response.
• GET Requests a representation of the specified resource.
• POST request is used to send data to the server to be processed.
• PUT Uploads a representation.
• DELETE Deletes the resource.
• TRACE Echoes back the received request such that a client can see what intermediate servers are adding or changing in the request.
• OPTIONS Returns the HTTP methods that the server supports for specified URL.
• CONNECT Converts the request connection to a transparent TCP/IP tunnel.

HTTP & HTTPS

HTTPS stands for Hyper Text Transfer Protocol Secure. A web site starting with https//: means that your computer is talking to the website in a secure code that no one can eavesdrop on. The primary difference between http and https is with the default port which is 80 for http and 443 for https.