HTTP(Hyper Text Transfer Protocol)

• HTTP is a stateless request-response application layer protocol.
• HTTP is used to build distributed, collaborative, hypermedia information systems.
• HTTP is the foundation for the worldwide web.
• Applications built using HTTP subscribe to the client-server computing model.
• In the client-server computing model a host designed to provide a service is called a server.
• Clients are hosts that make requests to that service. The HTTP specification defines how requests and responses should be formatted, but not what a service should represent
• HTTP is often associated with serving .html files but is also used to transfer images, videos, .json, .xml, binary executables, and much more.

HTTP Requests

A HTTP/1.1 request is formatted in text and transferred using TCP. The first line of the request contains the METHOD, URL, and HTTP VERSION. The following lines are the request HEADERS. Each header is separated by a newline character. A header is a key value pair separated using a colon. Headers containing more than one value separate each value using a semicolon. The header section of the request is terminated with an empty line. An optional body follows the header section.

HTTP Response

A HTTP/1.1 response is also formatted in text and transferred using TCP. The first line of the response contains the HTTP VERSION, STATUS CODE, and STATUS MESSAGE. The following lines are the request headers and are formatted exactly the same way as the request headers. The header section of the request is terminated with an empty line. An optional body follows the header section.

REST

REST is acronym for REpresentational State Transfer. In layman’s terms, is a means by which we can reference, manipulate, and transfer state. Rest uses a common set of methods (called “verbs”) to operate on the state of a resource (“noun”), generally using HTTP as the transfer protocol.

A “RESTful Endpoint” is a URI that identifies the resource. When addressed with a proper method, you are able to effect state. In normal terms, this means “Performing CRUD operations over HTTP