HTTP -HYPER TEXT TRANSFER PROTOCOL

HTTP stands for Hyper Text Transfer Protocol. HTTP is an application protocol for distributed and collaborative information systems. HTTP is the foundation of data communication for the World Wide Web.

HTTP functions as a request response protocol in the client server.  The client submits a request message to the server. The server which performs certain actions to the submitted request issues a response message. 

For example, web browser is a user agent or client and the system where the application running on a computer may acts as a server.

HTTP resources are identified and located on the network by uniform resource locator and uniform resource identifier schemes like http and https. URIs and hyperlinks in HTML documents form interlinked hyper text documents.

HTTP methods are the desired action to be performed on the identified resource. The resource may be already existing data or dynamically generated data on the server. HTTP methods are
    
      GET

POST

HEAD

PUT

DELETE

TRACE

OPTIONS

CONNECT

       PATCH

Out of all these methods the first two i.e, GET and POST methods are commonly used.

GET requests retrieves data from the web server.

POST requests are used to send data to the server.

HEAD requests are similar to GET. They also retrieve data but only with response lines and headers and not the entity body. 

PUT method requests that the enclosed entity be stored under the supplied URI.

DELETE method is used to request the server to delete a file at a location specified by the URL.

CONNECT requests are sent by the client to the server to establish a network connection with the web server.

OPTIONS methods are used to return the HTTP methods and other options supported by the web server.