Assign Learning to My Team action

Hello everyone

I need to assign learning to my team but first of all I need to know the difference between "Person" "Organization" and "Directs" al the level of Learners section. I've attached the screen for more clarify

I'd like to receive answer at the question below:

• If select "Person" which user can I select?
• If select "Organization" which user can I select?
• If I select "Direct" which user can I select?

Thank you