If anybody ever needs to know the difference between VMs and Docker, check out the below links:
https://blog.docker.com/2016/03/containers-are-not-vms/ (short read)
https://medium.freecodecamp.org/comprehensive-introductory-guide-to-docker-vms-and-containers-4e42a13ee103 (long read)
i thought these were pretty good in their explanation!