In USB connectors, "Gen1" and "Gen2" refer to different generations of USB 3.x versions, and their main difference lies in data transfer speed and performance.
In short:
USB 3.2 Gen 1 (also called USB 3.0 or SuperSpeed USB) has a maximum transfer speed of 5 Gbps, which is much faster than USB 2.0 (up to 480 Mbps), but still not as fast as Gen2.
USB 3.2 Gen 2 (also called USB 3.1 or SuperSpeed+ USB) has a maximum transfer speed of 10 Gbps, which is twice as fast as Gen1.
To sum it up:
Gen1: Maximum transfer speed 5 Gbps.
Gen2: Maximum transfer speed 10 Gbps.
These two standards are usually seen on USB Type-C and USB-A interfaces, and the main difference is the difference in transfer speed and bandwidth.
USB3.0 A
USB3.0 B
USB3.1 Type-C
