What is the difference between a Facebook admin and moderator?

I have a few members on my Facebook group who I am considering making into moderators. I am just unclear on what the roles are between a Facebook administrator and moderator and how much control each has over a group. I did try looking for answers to my questions on Facebook community forums and contacting Facebook customer service for answers to my questions and they are somewhat helpful but they don't address all of my concerns and there doesn't seem to be any Facebook support that can explain this.

So I just want to ask if anyone here who is more familiar with the site can answer my questions. I do know that both moderators and admins can either accept or decline group member requests and that they can remove posts that appear to violate the community rules...but which can remove or block members? Also, can either one close out the entire group altogether, or is it only the creator of the group or other admins who has this power? Just want to be sure because I want to show appreciation for the group's best members without doing something I might regret. Hopefully someone can also direct me to a page that can answer these questions more specifically.