Http Request Response Cycle

The HTTP protocol is very structured and consists of a very well-defined set of steps:

• Open the connection. The client opens a TCP connection to the server. The port will be port 80 for HTTP connections and 443 for HTTPS (secured) connections.
• Send the request. The client will now send the HTTP request to the server. The request contains the following information:
  • An HTTP method. It can be any of them (i.e. GET, POST, PUT, DELETE, etc).
  • A URI (or Uniform Resource Identifier). This specifies the location of the resources on the server.
  • The HTTP version (usually HTTP/1.1 or HTTP/2).
  • A set of headers. They include extra data related to the request; there is a full list of HTTP headers that can be used here.
  • The optional body. Depending on the type of request, you’ll want to also send data, and the data is encoded inside the body of the request.
• Request processed by the server. At this stage, the server will process the request and prepare a response.
• Send the HTTP response back to the client. Through the open channel, the server sends back an HTTP response. The response will contain the following elements:
  • The HTTP Version.
  • The status code. There is a list of potential status codes that describe the result of the request.
  • A set of headers with extra data.
  • The optional body, just like with the request, the body of the response is optional.
• The connection is closed. This is usually the last step, although with newer versions of the protocol, there are options to leave the channel open and continue sending requests and responses back and forth.