What is a multi-stage build in Docker primarily used for?

A multi-stage build in Docker is primarily used to create smaller, more efficient images. This approach allows developers to break down their build process into multiple stages within a single Dockerfile. Each stage can use a different base image and can perform specific tasks, such as compiling code or installing dependencies, without carrying along unnecessary files or dependencies into the final image.

By isolating the build process into distinct stages, only the essential artifacts needed to run the final application are included in the final image. This practice significantly reduces the size of the image by excluding development dependencies and other files that are not necessary for the application to run in production. The result is a leaner image that consumes less disk space and network bandwidth, making it quicker to transfer and deploy, as well as improving performance when running in a containerized environment.

While other options may involve aspects of Docker and container management, they do not specifically address the primary advantage of multi-stage builds, which is focused on optimizing the size and efficiency of Docker images.