Docker or Podman¶
Before going further, here are quick and simple definitions of what a container is and what a composer is, these definitions are important and must be well understood before starting.
Two engines, same definition
Both of the definitions described below are valid for either Docker or Podman. 
Container definition¶
A container is a standard unit of software that packages up code and all its dependencies so the application runs quickly and reliably from one computing environment to another. A container image is a lightweight, standalone, executable package of software that includes everything needed to run an application.
Composer definition¶
A composer is a tool for defining and running multi-container container applications. With Compose, you use a YAML file to configure your application’s services. Then, with a single command, you create and start all the services from your configuration.