Why are switches needed?

Question

network hardware

I just saw a server cabinet, and there is a switch as they said.

Answer 1

although it is not obvious from their name, they are needed for switching.
https://ru.m.wikipedia.org/wiki/Network_switch

Answer 2

What is the fundamental difference between switching and routing.
So, when switching (on the switch), the packet is switched from port to port. The switch does not know where to send the packet (to which host?), but it guesses that it needs to be thrown out to the right port. The switch passively listens for traffic, collects statistics and makes a decision based on it.
And with routing (on the router), it is the direction along a certain route that occurs. Go there through something. And this direction is set from somewhere outside (by a person or by a routing protocol). The router knows where it needs to send the packet (to which host or to which network), and based on this knowledge, it chooses the output interface port.