The full name of USB4 is Universal Serial Bus Generation 4, which is the latest generation USB specification released in September 2019. It supports 20Gbps and 40Gbps transmission speeds and can provide up to 100W of power. Only USB Type-C connector is used, which is dual-channel transmission. It can also transmit DisplayPort video and audio at the same time, and is backward compatible and supports Thunderbolt 3.

The differences between USB 3.2 and USB4 are as follows:

1. Transmission bandwidth: USB 3.2 maximum is 20Gbps, while USB4 is 40Gbps.

2. Transmission protocol: USB 3.2 mainly transmits data through the USB protocol, while USB4 encapsulates the protocol into data packets through tunnel technology.

3. DP transmission: Both of them can support DP 1.4.

4. PCIe transmission: USB 3.2 does not support PCIe, USB4 supports.

5. TBT3 transmission: USB 3.2 does not support, USB4 supports.

6. Host to Host: The communication between host and host is not supported by USB3.2, but is supported by USB4.