What is the main purpose of using multi-stage builds in Docker?

The primary purpose of using multi-stage builds in Docker is to optimize image size and the build process. This technique allows developers to define multiple stages in a single Dockerfile, where each stage is responsible for a specific task, such as compiling code, running tests, or packaging the final application. By separating these tasks into distinct stages, it becomes possible to copy only the final artifacts needed for production into the final image, while excluding unnecessary build dependencies and files from earlier stages.

This results in a significantly smaller image size, which can lead to faster deployment times and reduced storage costs. Additionally, multi-stage builds can streamline the build process by allowing developers to manage dependencies and build environments more effectively, as they can maintain a lean final image without including all the tools and libraries required for the build process itself.

This approach not only enhances efficiency in image management and distribution but also contributes to better performance and security by minimizing the attack surface of the final image.