1.STAR TOPOLOGY-
                IN THIS TOPOLOGY ALL THE NODES ARE CONNECTED TO A CENTRAL NODE WHICH FURTHER REBROADEAR ALL THE TRANSMISSION RECIEVED FROM  ONE NODE TO ANOTHER NODE IT IS POINT TO POINT CONNECTION BETWEEN TWO DEVICES
REQUIREMENTS-
            1.HUB
            2.UTP CABLE
            3.CAT 5 CABLE
            4.CONNECTER RJ45 (REJISTER JACK)
            5.NIC
SPEED-
       HUB:10mbps
       SWITCH:100mbps
       LAN CARD:10/100mbps
  IEEE define star topology as :
If we use HUB: 10 base T
If we use SWITCH :100 base T

100 base fx is define to use fiber optic cable. 
we are using straight cabling for establish star 
topology.