What is the main difference between the router WHAT IS THE MAIN DIFFERENCE BETWEEN THE ROUTER & A SWITCH a switch ?

Router used to communicate between two different network but Switch used to work in single network.

For example :   if we have two network like 192.168.10.0 and 172.158.25.0 here router have only capacity to communicate between these networks but Switch cannot make communication between them.

Note: Only layer 3 switch has capability to work as a router.