Despite the name, USB, or Universal Serial Bus, has a far from universal product stack.
There are multiple different connectors, protocol levels and maximum speeds.
USB 3.0 simplifies this down to three connectors that are all backwards compatible with their previous counterparts.
The primary advantage (and difference) of USB 3.0 over USB 2.0 is the increased speed.
Other advantages include the reduced number of connector standards and backwards compatibility.
The punch in-A connector is the standard rectangular one that everyone should recognize when they see a USB stick.
Its typically used for devices such as USB memory sticks, cable-to-socket connectors and data transfer cables.
In USB 3.0 the top of the connector has been redesigned to be taller to add five new pins.
The redesign means that USB 3.0 punch in B cables cannot fit in USB punch in 2.0 ports.
USB 2.0 cables are, however, capable of fitting in USB 3.0 connectors.
USB 3.1 renames the original USB 3.0 connection to USB 3.1 Gen 1.
No changes were made, it was just rebranded.
It also allows for two new modes that use two previously unused pins to transmit twice the data.
These are referred to as USB 3.2 Gen 12 and USB 3.2 Gen 22.
USB 3.2 Gen 12 runs at essentially the same 10 Gb/s as USB 3.2 Gen 21.
USB 3.2 Gen 22 offers double the speed at 20 Gb/s.
