Container technical fundamentals

Containers can currently be deployed in two ways: using Docker and through an orchestration method such as Kubernetes (K8s), both of which will be addressed in this chapter in a bit more detail. The fundamentals described in this section apply to both.

Think of an OS in two parts: the core functionality and APIs, and the presentation layer. A command-line interface or graphical user interface (GUI) is just an application/presentation layer that interacts with the core OS. It is the core OS that is virtualized across different containers.

A container image is the most fundamental component in the container ecosystem and is published to a registry. Microsoft provides SQL Server container images that are based on Docker. Docker is what allows you to build a container image, but it also allows you to run an image. Docker runs natively on many OSes, which makes it convenient for developers to write container-based applications.

By default, storage...