= Network switch
{wiki}
A switch is a box with a bunch of <Ethernet> wires coming into it:
``
+--------------------+
| +-+ +-+ +-+ +-+ |
| |1| |2| |3| |4| |
| +-+ +-+ +-+ +-+ |
+--------------------+
``
Except that it doesn't have to be <Ethernet>, e.g. it would also be a <Wi-Fi>.
What the switch does is:
* an <Ethernet> request came in from wire 1
* decide which wire to send it out on, e.g. wire 2, 3, 4, 5, etc. You likely don't want to send it back through 1 where it came from.
After the destination is found, a confirmation is somehow sent back to the switch, which then learns which wire to send each <MAC address> to.
A switch is a bit like a <router> but it is a bit dumber/operates at a lower level: it basically operates only on <MAC addresses>, not on <IP addresses>.
The <Internet service provider> boxes most people have at home combines a switch for the local network and a <router> for the ISP communication.