can someone expllain me what is switching fabric is
So this means
Switch fabric is the combination of hardware and software that moves data coming in to a network node out by the correct port (door) to the next node in the network.
so if data comes to port fa0/1 then switch fabric takes care if data is to be moved for e.g on same network say port fa0/10
or if to different network then switch fabric will move data to Port connected to router right ?
Yes correct. If it is a different network it still might be on the same switch if it is a L3 switch and it the destination device could be on a different linecard if it is a switch like the 4500 or 6500 so the switch fabric would still be used to move the packet through the switch to the correct port.