What is a Dominant?

I was chatting early this morning while on a boring duty at work. We were talking about my being submissive and having a Dom, which he jokingly referred to as Adult Simon Says. My friend (who is not kinky) said he thought dominating sounded really hot. I said "There's more to it than bossing girls around." 

"Hmm... I'm interested... What is it to being a Dom then??"

I thought about it. For an hour and a half. I know what I know. I know what I need. I have been in D/s relationships. I have dominated pet. There is SO MUCH more to being a Dom. But I was stumped.

"Good question. Been trying to come up with an answer. I feel it, but can't come up with words. (Rare for me.)"

A Google search had 34,700,000 results for 'What makes a good dominant'. I knew I wasn't the first to try and put it into words.

I still don't know what to say. So I thought I would put the question out to everyone.

To all of my D-type and s-type friends and readers:
 

What is a Dominant?