What distinguishes a Docker image from a Docker container?

The distinction between a Docker image and a Docker container lies primarily in their fundamental characteristics and roles in the Docker ecosystem. A Docker image serves as a static template that encapsulates the application code, libraries, and environment settings needed to run an application. It is essentially a read-only file that provides all the necessary components and specifications required to create a container.

On the other hand, a Docker container represents a runnable instance of that image. When a container is created from an image, it becomes an isolated environment where the application can execute. This environment is dynamic and can be modified during runtime, as containers can maintain their own states, file systems, and configurations.

This understanding of the roles of images and containers clarifies why stating that an image is a static template while a container is a runnable instance precisely captures their functions. The other options fail to accurately describe their characteristics, leading to confusion about the nature of images and containers within Docker.