1 00:00:00,700 --> 00:00:02,770 When you connect devices together so 2 00:00:02,770 --> 00:00:07,140 that they can talk to each other, you create what's called a network. 3 00:00:07,140 --> 00:00:10,950 One way to accomplish this is with routers and switches. 4 00:00:10,950 --> 00:00:16,250 Routers are intermediary devices that route data to its correct destination, 5 00:00:16,250 --> 00:00:21,490 meaning routers connect multiple networks in order to move data around. 6 00:00:21,490 --> 00:00:24,470 Switches physically connect local networks. 7 00:00:24,470 --> 00:00:27,290 And while switches have a similar purpose to routers, 8 00:00:27,290 --> 00:00:30,580 switches are much less intelligent than routers. 9 00:00:30,580 --> 00:00:33,920 Now let's learn about how switches create a local network and 10 00:00:33,920 --> 00:00:35,490 routers connect those networks. 11 00:00:37,140 --> 00:00:40,180 A router is made to take data packets destined for 12 00:00:40,180 --> 00:00:45,180 places outside the local network, and move them from point A to point B. 13 00:00:45,180 --> 00:00:49,500 Just like clients and servers, routers use protocols to talk to each other and 14 00:00:49,500 --> 00:00:52,870 figure out the more efficient way to send each packet of data 15 00:00:52,870 --> 00:00:56,110 from one router to the next, until the destination is reached. 16 00:00:57,270 --> 00:01:01,360 In order to work efficiently, routing packets along the best path for 17 00:01:01,360 --> 00:01:03,270 their final destination, 18 00:01:03,270 --> 00:01:07,740 each router keeps information about other routers in what's called a routing table. 19 00:01:08,780 --> 00:01:12,720 When a packet is received, a router examines the packet and determines where 20 00:01:12,720 --> 00:01:16,180 it needs to go next, using the information from the routing table. 21 00:01:17,250 --> 00:01:21,760 To do this, a routing table contains at least three bits of information. 22 00:01:21,760 --> 00:01:23,029 The network ID, 23 00:01:23,029 --> 00:01:27,770 the cost, meaning how efficient the path is that a packet is to be sent, and 24 00:01:27,770 --> 00:01:33,760 the next hop or gateway the packet will go to on its way to its final destination. 25 00:01:33,760 --> 00:01:38,440 Another piece of hardware that bridges the gap between computers is a switch. 26 00:01:38,440 --> 00:01:41,590 A switch is similar to a router in that it also contributes 27 00:01:41,590 --> 00:01:43,490 to a network's efficiency. 28 00:01:43,490 --> 00:01:47,440 However, a switch manages the flow of data across a network 29 00:01:47,440 --> 00:01:52,310 in a slightly different way, by physically connecting devices together with cables. 30 00:01:53,480 --> 00:01:58,461 When a switch connects devices of a school, computer lab or office together, 31 00:01:58,461 --> 00:02:02,087 it creates what's called a local area network, or LAN. 32 00:02:02,087 --> 00:02:04,694 While you probably don't have a switch at home, 33 00:02:04,694 --> 00:02:07,619 since there are few ports built into your home router, 34 00:02:07,619 --> 00:02:12,480 you might be using one at school or work, maybe even without knowing it. 35 00:02:12,480 --> 00:02:17,130 With switches creating networks and routers connecting networks, 36 00:02:17,130 --> 00:02:20,940 we've created a wonderfully fast and efficient process to move 37 00:02:20,940 --> 00:02:25,830 data around our community and world, but that's not the end of the story. 38 00:02:25,830 --> 00:02:28,510 Stay tuned to learn about a few more pieces of hardware and 39 00:02:28,510 --> 00:02:32,430 software that get the Internet all the way to your laptop at your house.