title: Airflow: what do `airflow webserver`, `airflow scheduler` and `airflow worker` exactly do?
body: <p>I've been working with Airflow for a while now, which was set up by a colleague. Lately I run into several errors, which require me to more in dept know how to fix certain things within Airflow.</p>
  
  <p>I do understand what the 3 processes are, I just don't understand the underlying things that happen when I run them. What exactly happens when I run one of the commands? Can I somewhere see afterwards that they are running? And if I run one of these commands, does this overwrite older webservers/schedulers/workers or add a new one?</p>
  
  <p>Moreover, if I for example run <code>airflow webserver</code>, the screen shows some of the things that are happening. Can I simply get out of this by pressing CTRL + C? Because when I do this, it says things like <code>Worker exiting</code> and <code>Shutting down: Master</code>. Does this mean I'm shutting everything down? How else should I get out of the webserver screen then?</p>