Cat 3: Max 10 Mb/s, 16 MHz bandwidth
Cat 5: 10/100 Mbps
Cat 5e: 10/100/1000 Mbps, 100 MHz
Cat 6: 10/100/1000 Mbps, 250 MHz, better in environment that has electromagnetic interference.
Cat 6a: 10,000 Mbps, 500 MHz
Cat 7: 10,000 Mbps, 600 MHz