I did not understand what the essence of the switch is! How does it work?

Question

WiFi

Well, in fact, as I understand it, if there are, for example: 8 connectors, that is, I want to connect a cable that will give out the Internet. Where to connect the main cable that will give out the Internet, and other computers (or routers, routers) will be connected to other connectors and what would it work?

Answer 1

Everything is quite simple:
Switch - switches / connects.
Router - routes/routes.

Answer 2

Switch - allows you to connect many devices (depending on the number of ports), connect physically, i.e. Simply by plugging in a cable from N number of devices you will not get a full-fledged network, additional settings are required.
But if a router (router) or a PC with a DHCP server is connected to the switch, all enabled devices will receive their IP addresses. Routers have this feature enabled by default.
You can include a cable from a provider that issues IP based on registered MAC addresses, all your devices will receive their IP addresses automatically.
In fact, the Switch is just a piece of iron, something like a tee or extension but a little more complicated.