Different between Virtual Machine and Docker, Docker does not virtualize the hardware and computing resource layer.

Docker image is a running instance of docker container.

"docker run -it hello_world", the "-it" is to run the container in the interactive terminal.

Dockerfile is a text document that contains all the commands a user could call on the command line to assemble an image.

the EXPOSE in Dockerfile is to expose your data file to your user.

You can use RUN in Dockerfile to install dependencies and libraries, eg. "RUN apt install python3"

Docker compose is to start multiple containers, put in the same virtual network.

"docker build -t image_name . ", this command build all the library, dependency, data, code into an image for deployment.

" docker run --rm image_name ", the container will be remove (--rm) after stopped.