They are basically files which consist of commands to tell the system who reads it what to do. Generally, they called Dockerfile
.
The file needs to be build
in order to used. Then an image
is produced.
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.
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.