It's not like that Docker containers share a single Python GIL but the thing is each Python process is a fork of the GIL which runs completely on its own thread. Docker does not share a GIL but it may share the resources on the host with other containers. This may have to do with the underlying virtualization within Docker. If you want to learn Docker then I would suggest you must learn it by taking any certification course, so this gives you many benefits such as you got the certificate which will further help you and you will have a decent knowledge of Docker. I would suggest you must take up the following Docker Training Course. I am also mentioning an awesome video tutorial which you must watch to learn all the basics about Docker.