[Observium] Observium poller/discovery module descriptions

I have searched your webpage and FAQ and can't seem to find answer to my question:

Do you guys have a list handy describing what each of the poller and discovery modules do exactly?

$config['poller_modules']['system'] = 1;

$config['discovery_modules']['os'] = 1;

I am working on a new deployment of Observium and am trying to optimize it and configure some custom requirements and it would be helpful having some additional information regarding each module.

Thank you!