Practicing Docker
Dockerfile
They are basically files which consist of commands to tell the system who reads it what to do. Generally, they called Dockerfile.
Image
The file needs to be build in order to used. Then an image is produced.
Container
Images are executables which are then called container. Inside containers, there would be an OS (*nix) and a running app on it.
Containers can be interactive in many ways like talking through protocols with each other/host, sharing file systems.
They are basically a computer with the most minimalistic setup.
Managing multiple containers
When several Docker containers exist, managing them manually gets hard. With this purpose, there is a tool called compose. It allows to define and run multiple containers.