You might heard about Cat 3 UTP cable, it's not popular anymore since it can only support 10 Mbps Ethernet network.
Cat 5 UTP cable can support 10/100 Mbps Ethernet network, whereas Cat 5e and Cat 6 UTP cable can support Ethernet network running at 10/100/1000 Mbps. The cable can be categorized as Cat 5, Cat 5e, Cat 6 UTP cable.