A Router is used to connect two or more LAN together to provide a WAN .GigabitEthernet ports are used to connect router to a LAN segment via Straight Through UTP cable or patch cable.Serial ports are used to connect routers to WAN.Console Ports is used to configure the router.
A LAN Card or Network Interface Card ( N I C ) is used for computer or any device that you wanted to connect to the network.Either LAN card or wireless LAN card is necessary in order that a devices can be connected to the network.
A HUB is used as a central device in a networks , but it does not break collision domain in the network. The HUB is serve as a repeater to extend the network range.