The main difference between Cat5, Cat6, and Cat7 cables is the speed and bandwidth that they can support.
Meanwhile, Cat5 cables can support speeds of up to 10Mbps, Cat6 cables can support speeds of up to 10Gbps, and Cat7 cables can support speeds of up to 40Gbps.
Lastly, Cat7 cables also have shielding that helps protect them from interference, while Cat5 and Cat6 cables do not.