Bandwidth is basically the rate at which data is transferred, it is usually measured in BPS (BITS per second), MBPS (Megabits per second) and KBPS (kilobits per second). So everything on the Internet would use bandwidth.
This is an image to help demonstrate bandwidth, but as cars and traffic. So following that basis, the more lanes you have the faster it will move but if you don’t have lots of lanes and you have lots of traffic coming through it will be slow.
Here is a short video on what bandwidth is, and I hope it can help:
So this was basically Bandwidth in a nutshell.