I will give you three reasons which will tell you why Docker is a winner versus VMs:-
Docker is very easy to start reason because Docker containers take milliseconds to start, VMs take minutes.
You can also run hundreds or thousands of containers on a single laptop, you can't run a fraction of that of VMs because they are much heavier weight.
Docker containers are also a favourite lightweight "packaging" format. Where developers can package their apps in containers that are easily published and consumed by others.
In the current world when everyone is shifting their products to the cloud you must learn Docker. Here is a Docker Training Course which you must take up to learn all about Docker. I am also mentioning a video tutorial which you must watch to learn more about Docker. .