What's the difference between Docker Compose vs. Dockerfile

I have been reading up and learning about Docker, and am trying to correctly choose the Django setup to use. So far there is either:

Docker Compose or Dockerfile

I understand that Dockerfiles are used in Docker Compose, but I am not sure if it is good practice to put everything in one large Dockerfile with multiple FROM commands for the different images?

I want to use several different images that include:

uwsgi
nginx
postgres
redis
rabbitmq
celery with cron

Please advise on what are best practices in setting up this type of environment using Docker.

If it helps, I am on a Mac, so using boot2docker.

Some issues I've had:

1. Docker Compose is not compatible with Python3
2. I want to containerize my project, so if one large Dockerfile is not ideal, then I feel I'd need to break it up using Docker Compose
3. I am OK to make the project Py2 & Py3 compatible, so am leaning towards django-compose

The answer is neither.

Docker Compose (herein referred to as compose) will use the Dockerfile if you add the build command to your project's docker-compose.yml.

Your Docker workflow should be to build a suitable Dockerfile for each image you wish to create, then use compose to assemble the images using the build command.

You can specify the path to your individual Dockerfiles using build /path/to/dockerfiles/blah where /path/to/dockerfiles/blah is where blah's Dockerfile lives.