It is likely that you have used one of the many network "Speed Tests".
Are they trustworthy? Do they really give us a measure of our network provider's service?
Here's a pointer to a piece that says "not really".
The TL;dr is that the performance of the network link between your home (or office) and the provider can not be reduced to a simple bandwidth number.
Most speed tests will give a very rough metric of your provider's quality when you are doing web browsing or watching a video. For many users that is sufficient.
But with the Covid-19 virus many of us are using the Internet in new ways, like holding meetings on Zoom.
As the piece points out, there are many characteristics that must be measured to get a full picture of how your path to the Internet will work for any given use.
These characteristics are complicated; they will probably bring a glaze to the eyes of most of us. But they are important and may be the difference between a happy and sad user.