CMD simply sets a command to run in the image if no arguments are passed to docker run, while ENTRYPOINT is meant to make your image behave like a binary.

1. If the Dockerfile uses only CMD, the specified command is executed if no arguments are passed to docker run.

2. If the Dockerfile uses only ENTRYPOINT, the arguments passed to docker run are always passed to the entrypoint; the entrypoint is executed if no arguments are passed to docker run.

3. If the Dockerfile declares both ENTRYPOINT and CMD and no arguments are passed to docker run, then the argument(s) to CMD are passed to the declared entrypoint.