What is docker and containers, how the docker containers help for running your application, deployment and CI/CD, refer the docker container document from the Docker portal docs.docker.com.

Let's begin forward the steps to install Docker in your machine, first you have to update the packages.

$ sudo apt-get update

then you need to install the dependencies, key and Docker using the following commands,

$ sudo apt-get install apt-transport-https ca-certificates curl software-properties-common

$ sudo curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -

$ sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu xenial stable"

$ sudo apt-get update

$ sudo apt-get install docker-ce

Once you have installed the Docker you can set permission for access the docker commands to the specific user without sudo permission,

$ sudo usermod -aG docker roruser

linuxfaq@linuxfaq:~$ docker --version
 Docker version 18.09.0, build 4d60db4