An image is a special file system. It provides programs, libraries, resources, configuration files and other files required for a running container. An image also contains some configuration parameters (such as anonymous volumes, environment variables, and users) prepared for a running container. An image does not contain any dynamic data, and its content is unchangeable after creation.
The relationship between the image and container is similar to that between the class and instance in the program design. An image is static, and a container is the entity for a running image. A container can be created, started, stopped, deleted, and suspended.
Multiple containers can be started for an image.
An application may include one or a set of containers.

What Are the Relationships Between Images, Containers, and Applications?