What is the purpose of the 'FROM' instruction in a Dockerfile?

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The 'FROM' instruction in a Dockerfile is essential because it defines the base image from which the new Docker image will be built. This instruction is fundamental to the Docker image creation process, as it acts as the starting point for the subsequent layers and configurations that will be added to create a customized image. By selecting a base image, you provide a foundational operating system and additional pre-installed software, libraries, or runtime environments that are needed to run your specific application or service within the container.

For example, if you are building a web application, you might start with a base image like 'ubuntu' or 'alpine' and then layer your application code, dependencies, and any necessary configurations on top of it. This modular approach also allows developers to build upon existing images, promoting reusability and efficiency in container deployments. The 'FROM' instruction is one of the first commands typically found in a Dockerfile, highlighting its importance in the image-building workflow.

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