Category 8 (Cat-8) Ethernet cables different than previous versions because they support a frequency of 2 GHz. Cat-8 is limited to a 30-meter 2-connector channel and also require shielding around the wire structures. Cat-8 can support speeds of 25 Gbps or in some cases 40 Gbps. The looks and physical appearance of cat8 are similar to the previous cables and can be terminated with RJ-45 or non-RJ-45 connections.
A major difference between Cat-8 and Category 7 (Cat-7) cables are the frequencies: Cat-7 is 600 MHz speed and cat-8 is about 2000 MHz speed.
Source: Category 8 (Cat-8)