In this chapter, we explored the Hyper-Text Transfer Protocol (HTTP), the technology used to exchange data across the web. We saw how requests and responses are simply well-structured streams of text or data exchanged across a packet-switched network. We examined the structure of these requests, and saw how they all use a similar pattern of a request or response line, a series of headers carrying metadata about the request or response, and an optional body.

We also discussed HTTP request methods like GET and POST, and HTTP response codes like a 404 and what these terms mean. We explored how HTTP has evolved from HTTP 1.0 to 1.1 to 2.0. And we discussed how HTTP is a stateless protocol, and how that statelessness is key to making websites that can serve thousands if not millions of users.

We’ll continue to reference the content of this chapter as we move forward, as HTTP is one of the core web technologies along with HTML, CSS, and JavaScript.