|       A hub is typically the least     expensive, least intelligent, and least complicated of the three.             Its job is very     simple: anything that comes in one port is sent out to the others.             Every computer     connected to the hub "sees" everything that every other computer     on the hub sees.             The hub itself is     blissfully ignorant of the data being transmitted. For years, simple hubs     have been quick and easy ways to connect computers in small networks.      Most devices now     are capable of both 10mps (10 mega-bits, or million bits, per second) as     well as 100mbs and will automatically detect the speed. If the device is     labeled with only one speed then it will only be able to communicate with     devices that also support that speed.      1000mbs or     "gigabit" devices are starting to slowly become more common as     well.              |            A switch does essentially what a hub     does but more efficiently. By paying attention to the traffic that comes     across it, it can "learn" where particular addresses are.                    If it sees traffic     from machine A coming in on port 2, it now knows that machine A is     connected to that port and that traffic to machine A needs to only     be sent to that port and not any of the others.             The net result of     using a switch over a hub is that most of the network traffic only goes     where it needs to rather than to every port.             On busy networks     this can make the network significantly faster.      Similarly many     devices now also include 802.11b or 802.11g wireless transmitters that     simply act like additional ports to the device.              |            A router is the smartest and most     complicated of the bunch. Routers come in all shapes and sizes from the     small four-port broadband routers that are very popular right now to the     large industrial strength devices that drive the internet itself.                    A simple way to     think of a router is as a computer that can be programmed to understand,     possibly manipulate, and route the data it’s being asked to handle.             All routers     include some kind of user interface for configuring how the router will     treat traffic.             The really large     routers include the equivalent of a full-blown programming language to     describe how they should operate as well as the ability to communicate with     other routers to describe or determine the best way to get network traffic     from point A to point B.              |     
   
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