Why is a USB port still installed in a current

How do I know if my computer has USB ports? usb 3 slot The Xbox one has three USB if that's what your asking, two on the back one on the left side usb slot I have 3 USB ports 1 is a and the others are I've tried plugging my mouse which is into both of my ports but they never work

usb 30 slot Bestor 3 Port High Speed Splitter Plug ,Data Transfer Adapter Expansion for PC Notebook Laptop Computer Mac Linux Windows HDMI Connector, USB Charger, USB Hub