Now you might be asking yourself, why do we need a set of rules for 0:00 two devices to talk to each other? 0:04 Aren't rules limiting? 0:06 Well, think about the way we hold phone conversations with family or friends. 0:08 The nature of your conversations probably varies widely from making dinner plans to 0:12 expressing sympathy from a loss, to catching up after a year or 0:17 two of losing touch. 0:21 However, all of these conversations probably follow a set of conventions. 0:23 First, there's some sort of greeting. 0:28 Hello? 0:30 Hi Courtney, this is Chris. 0:31 Or some variation of that. 0:33 What follows is a series of comments and sequence. 0:35 As in, one person talks, then the other, but 0:37 never at the same time where neither person is heard by the other. 0:41 And if a question is asked, well, a response quickly follows. 0:44 Unless there's no response, which can be unexpected or just plain awkward. 0:48 Both people know the conversation is over when each person says, goodbye or 0:53 talk to you soon. 0:57 Communication between devices over the internet is not 0:59 unlike spoken language over the phone. 1:02 Except that there are even more rules, to make sure machines don't end up 1:04 guessing what question was asked or what answer was given. 1:08 You might equate this rigid communication environment to a court room. 1:11 Where the judge won't response to an attorney shouting, hey or 1:15 no you didn't, but would respond to a simple objection. 1:18 Likewise, in internet communication word choice matters. 1:24 If the internet was going to be successful, 1:29 it required a set of standards for device communication. 1:31 That is, communication between the devices that contain the information and 1:34 the devices that wish to interact with it. 1:38 So, when Tim Berners-Lee and his team proposed the World Wide Web project 1:41 in 1989, what soon followed was the first published version of HTTP. 1:45 This was HTTP 0.9 in 1991. 1:50 The HyperText Transfer Protocol is the setup rules that 1:53 governs the messaging between devices over the Internet. 1:58 It functions mainly as a request-response cycle between a client and a server. 2:01 That is, a client makes a request and a server responds. 2:07 Examples of clients are a web browser, such as Chrome or Safari, 2:11 a native mobile app on iOS or Android like the Facebook app on your phone. 2:15 Or even a in a desktop weather application like one written in JavaFX. 2:19 The main example of a server is a web server such as Apache, 2:23 Nginx and Node.js server or even a Java enabled web server like Tomcat. 2:28 After a quick break let's see HTTP in action 2:34 using a simple text-based tool called Telnet. 2:37