Ansible - List of Managed Nodes

[Trevor]

Ansible automates tasks on managed nodes (or hosts) in a network,
using a list, or a group of lists.    What is this list, or group of lists
called?

[Chetan_Tiwary_]

@Trevor for this difficult question, I will drop a hint : check your inventory.

[Trevor]

Chetan, I was going to say to any readers of your post,
that if you refer to a question as difficult, that it's going
to require some knowledge well above RHCE.  I was 
looking for a smiley face, but I didn't see one.  Well, when
I saw your hint, I see why there was no smiley face.  
You're too generous