Differnces between hub, roter and switch

1. Hub
very primitive device. It creates a network between computers. it is impossible to manage it. If one computer send package to the another, this package is sending to the all computers  in the network

2. Switch
also create a network. One computer can send package to the another. Only this computer will receive this package

3. Router
connect networks. Links computer to the Internet. Via router you can send data between netorks