USB-C is one of the standards for charging and transferring data. It's included in devices like the newest laptops, phones, and tablets and will likely spread to everything that currently uses the older, larger USB connector. The specifications for USB-C were first published in 2014. It is fast becoming to be a real replacement for not only older USB standards, but also other standards like Thunderbolt and DisplayPort. USB-C is closely intertwined with other new standards, as well—like USB 3.1 for faster speeds and USB Power Delivery for improved power-delivery over USB connections.
USB Type-C has a new, tiny physical connector about the size of a micro USB connector. The USB-C connector itself can support various new USB standards like USB 3.1 and USB power delivery. USB Type-C offers a new connector standard that's very small. This is a single connector standard that every device should be able to use. You only need a single cable, whether you're connecting an external hard drive to your laptop or charging your smartphone from a USB charger. That one tiny connector is small enough to fit into a super-thin mobile device, but also powerful enough to connect all the peripherals you want to your laptop. The cable itself has USB Type-C connectors at both ends.
USB Type-C can also support several different protocols using "alternate modes," which allows you to have adapters that can output HDMI, VGA, DisplayPort, or other types of connections from that single USB port. The mess of USB, HDMI, DisplayPort, VGA, and power ports on typical laptops can be streamlined into a single type of port.
The USB Power Delivery specification is also closely intertwined with USB Type-C. Currently, a USB 2.0 connection provides only up to 2.5 watts of power; enough to charge your phone or tablet. The USB PD specification supported by USB-C ups this power delivery to 100 watts. It’s bi-directional, so a device can either send or receive power. And this power can be transferred at the same time the device is transmitting data across the connection. This kind of power delivery can let you charge a laptop, which usually requires up to about 60 watts.
While the physical USB-C connector isn’t backwards compatible, the underlying USB standard is. You can't plug older USB devices into a USB-C port, nor can you connect a USB-C connector into an older, larger USB port. But that doesn’t mean you have to discard all your old peripherals. USB 3.1 is still backwards-compatible with older versions of USB, so you just need a physical adapter with a USB-C connector on one end and a larger, older-style USB port on the other end. You can then plug your older devices directly into a USB Type-C port.