The basic function of a router is to connect one network to another. They are most often used to connect a home network to the internet. But they can be used to connect any two networks, such as those between computers. There are two types- wireless and non wireless.
Network Switches, or Cisco Switches as they are otherwise known, are useful computing devices that you may or may not already own. These devices play an integral part in helping you build local area networks in your home meaning you can share information from computer to computer.