1. USB 3.2 Gen 1( USB3.0 and USB3.1 GEN 1 equals to USB3.2 Gen1)
USB 3.2 gen 1's speed width is 5Gbps, in theory, the max speed could be gained after divide 10 times of width because it uses the same 10bit transmission speed with SATA, so its speed is 500MB/s, most mainstream portable hard disk, and some U disk uses this protocol too.
2. USB 3.2 gen 2
Its speed width is up to 10Gbps, because it reverses some width to achieve other functions, hence the effective width is around 7.2Gbps and convert into the 720Mb/s speed.
3. USB 3.2 gen 2*2
The Speed could reach 20Gbps, but is not commonly used, so here will not give much introduction.
4. USB 4.0
Its width is 40Gbps and based on Thunderbolt 3, but it is different from Thunderbolt 3, so both of them are not fully compatible.
5. Thunderbolt 3 - the strongest protocol developed by Intel and Apple Companies
Thunderbolt 3 protocol also has a 40Gbps width, so it could realize the things that ordinary USB protocols couldn't make.
1) Connect to Display Card, small and think laptop normally uses integrated card with only basic features, so when you need to play games or handle videos, the display card will not be sufficient, then under this situation, you could connect to a display card extension hub.
2) Connect to multiple LED screens, For example, Apple Macbook Pro has 4 USB C thunderbolt Connectors, you could connect with 4pcs 4K@60HZ display screen and work smoothly.
3) Support Bi-directional high power supply.
6. How to know if your laptop has a USB C connector with USB 3.1 protocol or Thunderbolt 3 protocol?
It will have a sign in your laptop of"SS" to show it's a USB3.1 protocol and a "lightning" sign to show a Thunderbolt protocol.