Discovering HTTP

- Hypertext transport protocol is an…application layer protocol for the web.…HTTP uses TCP as the transport layer protocol.…We're gonna focus on HTTP version 1.1,…it is the most widely used.…In this graphic, as we've seen before,…we see on the left-hand side the TCP/IP model,…on the right-hand side we see the OSI model.…Then within the center we see protocols and services.…

We see here that HTTP is in the application layer.…There are two types of HTTP messages;…requests from a client, and then a response.…Now a web page consists of objects.…Those objects can be something like the images,…the HTML file itself, and JavaScript.…Now we want to ensure that we get all of those objects,…so that your web page can be rendered correctly.…HTTP is a stateless protocol,…meaning the server maintains no information…about past client requests.…

An HTTP request message begins with a request line,…indicates GET or POST method,…a Uniform Resource Identifier, or URI.…This is different from the URL, or Uniform Resource Locator,…in that a URI indicates where on the page you'll find…