What is "interactive" in the docker container

What is exact meaning of attaching the STDIN into the docker container, What was the purpose of the flag --interactive in docker run command.

docker run --tty –interactive nginx:latest /bin/bash

Without --interactive, the typed in input is ignored.

You might want to use a “bare os image” for testing purposes. Simply compare the behavior of docker run --tty alpine /bin/sh and docker run --tty --interactive alpine /bin/sh.

You will see that both will display a terminal, but only the one with --interactive actualy reats to your input.