USB3.1 (also called Gen.2) brings many improvements to the previous standard USB3.0 (Gen.1). The most noticeable is the new Type-C connector which is much smaller and reversible. The Type-C connector is backwards compatible and can be used with USB2.0 PCs and devices.
Type A to Type C
This cable features both a Type-A connector and a Type-C connector making it the perfect solution for connecting modern mobile devices with a Type-C connector to a PC that doesn’t have a Type-C socket, only a standard USB2.0 connection
The new USB Type-C connector is smaller than most of the previous USB connectors. (Micro B is the exception.) It is also symmetrical; this allows you to plug the connector in either way up.