Have you ever tried on pants that were two sizes too small? Bandwidth is like those pants, but instead of legs, its packets of data. So, if you have bigger pants, you can fit more into them. So, if you want to send more data for a better quality stream, you will need more bandwidth to fit it all in, just like your pants before the county fair.

Bandwidth, measured in bitrate, measures internet connection speed or the amount of data that can be transferred/consumed. The higher the bitrate, the higher the resolution and the higher the required bandwidth.