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What is an image

When a developer uses docker, they create an app or service and package it along with its dependencies into a container image

An image is a static representation of a service of an app and its configurations and dependencies

It is this image that, when run, becomes the container, the container is an in-memory instance of an image.

A container image is immutable. Once you've built an image, the image can't be changed. Since you can't change an image, if you need to make changes, you'll create a new image. This feature is our guarantee that the image we use in production is the same image used in development and Quality Assurance (QA).



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