This note concerns private customers only, not professionals.
While Wi-Fi works well most of the time, working from home and frequent video chat are better handled by Ethernet cables which offer a lower latency, no dropped connections due to interference, and are just—at least theoretically—plain faster than wireless connections 1 .
Ethernet cables have different categories described in the table below (source).
| Category | Shielding | Max Transmission Speed (at 100 meters) | Max Bandwidth |
|---|---|---|---|
| Cat 3 | Unshielded | 10 Mbps | 16 MHz |
| Cat 5 | Unshielded | 10/100 Mbps | 100 MHz |
| Cat 5e | Unshielded | 1 Gbps | 100 MHz |
| Cat 6 | Shielded or Unshielded | 1 Gbps | 250 MHz |
| Cat 6a | Shielded | 10 Gbps | 500 MHz |
| Cat 7 | Shielded | 10 Gbps | 600 MHz |
| Cat 7a | Shielded | 10 Gbps | 1 Ghz |
| Cat 8 | Shielded | 40 Gbps | 1 Ghz |
My first thought was “the more, the better” but on closer inspection, anything with a transmission speed above 1 Gbps seems indigenous when most (all?) home customer Ethernet cards are gigabit card only.
Maybe there will be +10 Gbps card in a near future and you want to be prepare for it. However Category 7 and 7a are not recognized by the TIA/EIA-568 standard and are better avoided to prevent future problems.
As for now, Cat 6a is what most if not all home users should be using.
Standards are loosely respected
Unfortunately, according to tests by Blue Jeans Cable, compliance is loosely respected and your newly bought Cat 6 may only by as good (as bad?) as a Cat5a or below.
Again, unfortunately there is no easy way to test cables without specialized equipment that costs anywhere from $1,000 to $10,000.
It seems that private users can only either suck it up and hope for the best or buy from a reputable (and a little bit pricey) manufacturer like Blue Jeans Cable 2 .