What is the ARG instruction in a Dockerfile and how does it differ from ENV?

Question

Docker Fundamentals — Medium

What is the ARG instruction in a Dockerfile and how does it differ from ENV?

Accepted Answer

ARG in a Dockerfile defines a build-time variable only available during image build, while ENV sets an environment variable persisted in the image and available to running containers. This distinction is important for managing variables at different stages of the Docker workflow.