There are various generations of USB, with different capabilities and speeds, plus ports that look similar but do other things. Say you plug a USB 3.2 SSD into a USB 3.2 port on your computer, but use a USB 3.0 cable—data will only transfer at USB 3.0 speeds. USB Power Delivery (or USB-PD): If your laptop, tablet, or other device doesn't have enough USB ports, you might be forced to choose between charging or plugging in accessories. You'll want to make sure the wattage this USB-C port supports can handle what your laptop needs. There are a lot more types of USB connectors, but these are the two you're most likely to see in most hubs.