How Awesome it is.! Hyper Text Transfer Protocol (HTTP)

What is Protocol and HTTP?

• Protocol: A Protocol is a standard procedure for defining and regulating communication.. For example TCP, UDP, HTTP etc.

• HTTP is the foundation of data communication for the World Wide Web.

• The HTTP is the Web’s application-layer protocol for transferring various forms of data between server and client like plaintext, hypertext, image, videos and sounds.

Hyper Text Transfer Protocol

Terminology

• IP Address: An Internet Protocol address (IP address) is a numerical label assigned to each device (e.g., computer, printer) participating in a computer network that uses the Internet Protocol for communication.

• TCP: Transmission Control Protocol (TCP) is one of the two original core protocols of the Internet Protocol Suite (IP), and is so common that the entire suite is often called TCP/IP. TCP provides reliable, ordered, error-checked delivery of a stream of octets between programs running on computers connected to an intranet or the public Internet.

• Port Number: A port number is a 16 bit number which when associated with IP address , completes the destination address for a communications session.

• Socket: A socket is nothing but a combination of IP address and port number. It is simply an end while communication.

How HTTPS Work?

HTTP is implemented in two programs: a client program and a server program, executing on different end systems, talk to each other by exchanging HTTP messages.

• The HTTP client first initiates a TCP connection with the server. Once the connection is established, the browser and the server processes access TCP through their socket interfaces

PERSISTENT AND NON-PERSISTENT CONNECTIONS

In non-persistent connection each request/response pair are sent over a separate TCP connection.

• In persistent connections all of the requests and their corresponding responses are sent over the same TCP connection.

HTTP Request Message

The first line of an HTTP request message is called the request line; the subsequent lines are called the header lines. The request line has three fields: the method field, the URL field, and the HTTP version field.

 The method field can take on several different values, including GET, POST, HEAD, PUT, and DELETE etc.

The great majority of HTTP request messages use the GET method. The GET method is used when the browser requests an object.

HTTP Protocol