Stands for "Universal Serial Bus Type-C." USB-C is a type of USB connector that was introduced in 2015. It supports USB 3.1, which means a USB-C connection can transfer data up to 10 Gbps and send or receive up to 20 volts or 100 watts of power. Unlike the previous USB Type-A and USB Type-B ports, the USB-C port is symmetrical, which means you never have to worry about plugging in the cable the wrong way.
The USB-C connector is the most significant change to the USB connector since the USB interface was standardized in 1996. USB 1.1, 2.0, and 3.0 all used the same flat, rectangular USB-A connector. While there have been several variations of USB-B, such as Mini-USB and Micro-USB, they are all designed for peripheral devices, which connect to a Type-A port on the other end. The Type-C connector introduced with USB 3.1 is designed to be the same on both ends.
There is no mini or micro version of USB-C, since the standard USB-C connector is about the same size of a Micro-USB connector. This means it can be used in small devices like smartphones and tablets. Since USB-C supports up to 100 watts of power, it can also be used as the power connector for laptops. In fact, the first laptops to include USB-C ports – the 2015 Apple MacBook and Google Chromebook Pixel – do not include power connectors. Instead, the power cable connects directly to the USB-C port.
A USB-C connector will only fit in a USB-C port, but USB-C cables are backwards-compatible with other USB standards. Therefore, a USB-C to USB-A or USB-C to USB-B adapter can be used to connect older USB devices to a USB-C port. However, the data transfer rate and wattage will be limited to the lower standard.