Docker Image is the blue print that is used to create a Docker Container. Whenever we want to run a container we have to specify the image that we want to run.
There are many Docker images available online for standard software. We can use these images directly from the source.
The standard set of Docker Images is stored in Docker Hub Registry. We can download these from this location and use it in our environment.
We can also create our own Docker Image with the software that we want to run as a container.