Is Docker built from images?

Question

Docker

For example, there is a PHP + Nginx image
But I still need OS CentOS
Do I need to do for example docker pull PHPNginx and docker pull CentOS to create two images?
After all, it is considered correct - ONE CONTAINER = ONE SERVICE!

Answer 1

If you need OS CentOS on which php + nginx is installed, then create an image based on CentOS and install everything you need inside it.

docker pull PHPNginx and docker pull CentOS

- so you will separately unload two independent images