The Big Picture2:59 with Joy Kesten
The Internet is a world-wide network of computers that we use to watch videos (like this one), communicate with friends, and learn about the world. In this video learn more about the underlying technologies and protocols that run the Internet.
The Internet is a network of independent computers and 0:00 other hardware devices connected together. 0:03 You can think of this as a bunch of wires that let computers around the world 0:06 communicate with each other. 0:10 Connected to these wires are forests of other devices, 0:12 which make the Internet work like servers, routers, and switches. 0:14 The primary network in core routers around the world make up the backbone of 0:19 the Internet, and support the exchange of Internet traffic between countries, 0:23 continents, and across oceans. 0:27 Because of the diversity in hardware used all over the Internet, 0:30 everyone needs to work cooperatively. 0:34 The developers behind the software used on the Internet agreed to follow 0:36 a set of rules called protocols, when sending and receiving information. 0:40 Let's look at what's involved when you go to the homepage of your favorite website. 0:46 For the purposes of this example, 0:50 let's say your wirelessly connected to the Internet at your house. 0:52 After opening up a web browser and typing in a URL, your browser uses a special 0:56 protocol called HTTP or Hyper Text Transfer Protocol. 1:01 This is a set of rules for asking for and getting webpages. 1:07 But there's an even more basic set of protocols under this, called TCP/IP. 1:11 Which is short for Transmission Control Protocol and Internet Protocol. 1:16 These are the rules for sending and 1:21 receiving any data whether it's email, webpages or files on the Internet. 1:22 Once you initial your request TCP IP protocols take your request, 1:28 webpages, videos, or emails and break them into little packets of data and 1:33 send them in the fastest way possible. 1:38 From client to server and back again. 1:41 The TCP IP protocols are a fundamental part of the internet 1:43 which we'll learn more about later in another video. 1:47 After you request a web page TCP IP send your request wirelessly over 1:50 radio waves either to a router or directly to a wireless modem. 1:54 If you have a router what was a wireless request 1:58 is now sent along an ethernet chord to your modem. 2:02 Your modem then sends the packets along a coaxial cable or 2:05 phone line to the outside of your house where your internet service provider or 2:08 ISP connects you to the Internet. 2:12 The main network made of fiber optic cables and computers. 2:14 Once it reaches this point your request is now sent from one server to another 2:19 until it reaches the server that's hosting the website you wanted. 2:23 Then, the webpage you requested is returned in just the same way. 2:28 If this all happens correctly, the packets of data arrive, are reassembled, and 2:32 the web browser shows you a perfect copy of the webpage. 2:37 Usually this happens very quickly. 2:41 Often in just a matter of seconds. 2:43 So the internet has one job, letting computers and 2:46 other devices around the world to talk to each other. 2:49 But accomplishing that job is no easy task. 2:52 In the next few videos, let's look at each aspect of the internet in more detail. 2:55
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