Why is nginx not starting in a Docker container?

Question

Nginx

I make a standard dockerfile:
FROM nginx:latest
COPY ./index.html /usr/share/nginx/html/index.html
EXPOSE 80

But it doesn't want to open on the web. Apparently I'm missing a command or an item? Did according to the guide. There you build the container and then run it with the command docker run -it --rm -d --name web nginx001. But it still doesn't want to start.
I just know Docker and I want to understand what I missed

Answer 1

expose does not open a port.
You need to start by adding the key to docker run:
-p 80:80