Please explain me difference between uplink & trunk link.
uplink will forward normal traffic to other switches or any devices.
Normally the interface speed used for uplinks will be high.
Trunk link will be used for carrying vlan traffic to other switches or any other devices.
If you are using vlans on switches and you want that vlan traffic to be forwarded to other switches then you have to configure trunk links.
If you are not configuring trunk links then VLAN info will not be carried to other switches.