Difference Between Hub, Switch and Router

Hub	Switch	Router
In Hub signal introduced at the input of any port appears at the output of every port except the original  incoming. The device is a form of multiport repeater.	Network switch is a telecommunication device which receives a  message from any device connected to it and then transmits the message only to the device for which the message was meant. This makes the switch a more intelligent device than a hub	A router looks at packet headers to determine which port it needs to forward a packet through, and also will translate packets between different protocols if needed. A router can also define subnets and will filter traffic as needed. Routers usually include DHCP, port forwarding capabilities and a whole host of other things usually controlled by software and therefore user customizable.
A Hub is, in its simplest form, just like a mains multi plug unit. There is no intelligence or circuitry in it. More complex units may incorporate an amplifier or repeater. The network signal goes into one port and out of all the others.	A Switch has a small level of intelligence, in that it can open a message, check the IP address, and direct the message packets to the port on which the device with that IP address resides. It cannot modify IP addresses or see addresses outside of the range of the ‘home’ network	A Router can read IP addresses, and direct the messages to another network with different IP addresses to the originating network. The Router software can build up an address table, so that it ‘knows’ where other devices are.
Hub is a Physical Layer device, i.e. it operates at Layer 1.	Network switches are classified as Data Link Layer devices, i.e. they operate at Layer 2. However, certain multi-layer switches can operate at higher layers as well.	Router is a Network Layer device, i.e. it operates at Layer 3.
At least single network required to connect.	At least single network required to connect.	At least two networks are required to connect.
A Hub works on the basis of broadcast.	A switch works on the basis of MAC addresses.	A router works on the principle of IP addresses.
Less Expensive	More expensive	Much Expensive