Grant Fritchey shows how you can take a Docker container and save modifications:
There are much more sophisticated ways to get this done using Docker Files. However, this illustrates the point quite simply. You can customize your servers and then use those customizations. You don’t have to re-customize every time. Again, this is just a small slice of why containers are so powerful.
This method is great when you want to build out a sample data set, like when you’re running through automated testing and want to start from the same known point each time.