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Sarvesh Kesharwani
Sarvesh Kesharwani

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Difference between image and container in docker?

In Docker, an image is a read-only template that contains the instructions for creating a Docker container. It includes the application code, runtime environment, libraries, and other dependencies required to run an application. An image is like a snapshot of an application at a specific point in time.

A container, on the other hand, is a running instance of an image. It's a lightweight and portable executable package that includes everything needed to run an application, including the code, runtime environment, and system tools. When you run a container, Docker creates a writable layer on top of the image, allowing the application to store data and make changes to the container's environment.

Here are some key differences between an image and a container in Docker:

Image is a static entity, while container is a dynamic entity: An image is a snapshot of an application at a specific point in time, and it can be stored, shared, and used to create multiple containers. A container, on the other hand, is a running instance of an image, with a dynamic state that can change over time as the application runs.

Image is read-only, while container is writable: An image is a read-only template that cannot be modified once it's created. A container, on the other hand, has a writable layer on top of the image, which allows the application to store data and make changes to the container's environment.

Image can be shared, while container is ephemeral: An image can be shared between multiple systems or users, and it can be used to create multiple containers. A container, on the other hand, is an ephemeral instance of an image, and it only exists as long as the application is running.

Image defines the application, while container executes the application: An image contains the application code, runtime environment, and dependencies, while a container is responsible for executing the application based on the instructions defined in the image.

In summary, an image is a static template that defines the application, while a container is a dynamic instance of an image that executes the application and can be modified and interacted with during runtime.

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