Most common USB-C ports you encounter will be either USB 3.1 Gen-1 which is rated at 5Gbps (gigabits per second) the same speed as USB 3.0, or USB 3.1 Gen-1 (10Gbps). But then there’s the blazingly fast Thunderbolt 3 standard, which is nominally eight times faster at 40Gbps.
Most models will have the slower USB-C ports but high-performance laptops may have Thunderbolt 3 ports. You can plug a plain old USB-C device into a Thunderbolt 3 port but don’t expect any increase in speed. Plug in a Thunderbolt 3 device, such as an external SSD, and you have the fastest connection in town.
Even if you don’t have the Thunderbolt 3 version of this connection, USB-C is still a good thing to have, rather than just the old USB 3.0, because it's becoming widely adopted on computers and plug-in devices and expected to soon become the dominant connection port, eventually replacing USB 3.0.
One of the keys to USB-C’s swift adoption is its versatility – the same port can transfer both power and data at the same time and it's quite versatile. You can mimic a whole range of other ports – including USB 2.0/3.0, SD card, HDMI, ethernet and more – using a USB-C adapter.
However, try to stick with the manufacturer’s cables where possible and avoid cheap third-party cables and chargers or you may risk damaging your computer and peripherals. Use only certified USB-C and Thunderbolt 3 cables.