What is the difference between "expose" and "publish" in Docker?

Docker's EXPOSE and PUBLISH commands are used to control how containers communicate with the outside world. EXPOSE, used in Dockerfiles, informs Docker about ports the container uses, but does not make them accessible. PUBLISH, used when running a container, maps a container port to a host port, enabling access from outside the container. EXPOSE is informational and serves as documentation, while PUBLISH is an active operation that makes the application accessible beyond the container environment. EXPOSE helps plan networking and is used by orchestration tools, whereas PUBLISH binds the container's port to the host's. When writing a Dockerfile, always include EXPOSE to indicate the ports the application uses. Publish ports when you need external access to the containerized service. In development, EXPOSE may be sufficient for communication within the network, but for testing from outside, port publishing is necessary. In production deployments, port publishing is typically used, and orchestration tools may utilize EXPOSE for configuration. Key differences between EXPOSE and PUBLISH include: EXPOSE is a static declaration, while PUBLISH is a dynamic operation; EXPOSE indicates accessibility within the Docker network, while PUBLISH enables external access; EXPOSE is a note, while PUBLISH is an action. Best practices include always including EXPOSE in the Dockerfile for documentation, publishing ports only when necessary for security, using clear port mappings to avoid conflicts, and keeping configurations simple. Always test network settings to ensure proper communication.