There are a number of different types of USB-C to USB-C cables including: USB 2.0, USB 3.1 Gen 1, USB 3.1 Gen 2, and Thunderbolt 4.

The main difference between all of these is their data transfer rates and their charge rates. Basic charge cables give you very slow data transfer speeds and typically only up to 60 watts. For a phone, tablet, and even most small laptops such as a Dell XPS 13 or MacBook Pro 13 that's fine. As you move up to larger laptops such as a Dell XPS 15 or MacBook Pro 16, 60 watts will limit how fast you can charge.

The other key differentiator is speed. USB 2.0 is a plodding 480Mbps. USB 3 cables range from 5Gbps to 20Gbps. While USB4, and Thunderbolt 3 and Thunderbolt 4 can support up to 40Gbps of throughput.

Thunderbolt, USB4, and many USB 3 cables also support display support using DisplayPort.

USB-C cables today are used for transferring data, running monitors, and charging everything on the planet from $5 LED trinkets to $2,000 laptops and even power tools now. It is basically the most common type of cable for electronics today and thanks to its universal and open design it has rapidly replaced all other competitors including Apple's Lightning as well as older USB cables. It's appeal is the reversible nature so you no longer have to look for alignment. With its ability to handle 240 watts now, USB-C to USB-C cables will likely begin replacing other proprietary cables as well.

Obviously, one answer is the cable is simply bad or damaged, but if you’re finding that a brand-new cable that came with your $5 USB fan or $7 LED USB-trinket won’t transfer data at all, you're probably using the “free” USB-A to -C cable that came with that cheap device.

Many of these cheap cables contain wires that only supply power to charge that cheap trinket and don’t support data transfer at all. You can sometimes see this by looking into the square USB-A cable connector where only two connections are visible. A standard USB-A cable usually features at least four connections inside of it.

You can “fix” this by buying a USB cable that supports data transfers.