How to disable poormanscron?

Hi drupal experts

How do I disable poormanscron? And switch it on again? Is it enough to set both the "cron run intervals" and the "retry intervals" of poormanscron to zero?

I realise that this is a simple question. But I am looking for a simple, clear, to-the-point answer. I have not found it on drupal.org.

I know hardly anything about website development and maintenance. I have recently been abandoned by my webmaster (due to an health condition).

Thank you in advance for helping me.

Bye bye