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

• 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.
• A container is to an image what an instance is to a class in computer programming. 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.

Figure 1 shows the relationships between images, containers, and applications.

Figure 1 Relationships between images, containers, and applications