The technology Docker is used to make an image of your application along with the environment setup.
Docker is mainly used when you have a lot of services which work in an isolated manner and serve as a data provider to a web application. It depends on the load, the instances can be spun off on demand on the basis of the rules setup.
One can use Docker on local machines as well as the cloud. The best way to use docker is with Docker swarm flavour with Docker cloud. It enables one to fire off multiple instances and the services are discovered using the Docker cloud settings.
If you want to have a certificate in Docker then you can have a look at the following Docker Training Course. If you like to read then you can read the following tutorial on Docker. To watch the free video tutorials on Docker you can visit the below-mentioned website:-