I thought about this as well and realized that while both charisma and a charming nature can be 'natural' charisma is much more powerful.
Charismatic people aren't necessarily well-groomed, polite, or even pleasant. But they are strangely magnetic and can get people to pay attention in a positive way. Look at certain politicians, despots, and religious figures in ancient and modern history. Frankly, most of those men were and are absolutely NOT prizes in the looks department but some of them had/have that 'it' factor... Then again, some of what these men had going for them were political machines and access to lots of money, weapons, and inherited rank in groups but I'm sure some of them really were charismatic.
I think of charisma as more a natural 'X factor' thing that pulls people. Call them pheremones if you will. You can teach people to increase their 'personal power' or influence, but charismatic people attract people. Period.
There are definitely a handful of folks IRL who I think are varying degrees of charismatic. I might not even find them personally likeable, but I will admit they have a strange way of making disparate groups of people like and respect them (even when I don't). If you can only get popularity amongst one group of people, I don't consider that charismatic -- a truly charismatic person has a personal effect that everyone feels. Then again, you could say some people have 'strong auras' or strong presences, but it doesn't necessarily mean that people are drawn to them or they exercise influence over others, they just have a strong presence...um...damn, where am I going with this.
Well, anywhoo -- charm is more an expressive act that I associate with good manners, awareness, and a desire to make people feel good and being good at it Charm is knowing the right thing to say, at the right time, in the right way, and to the right person. It's not necessarily being fake, because some people genuinely enjoy uplifting people and the mood. associated more with being suave, smooth, and socially polished. People really enjoy being around charming people, however they are drawn to charismatic people. And again, charismatic people are not necessarily any of the things that make a person charming.
But wait...you could say everyone has their own personal 'charm' i.e. everyone's got their something. So I guess you could say 'charm' as a noun is that quality in you that is most attractive to people? So it can be different from person to person. Someone's charm might lie in their vulnerability and enthusiasm, and another's in their gruffness and sarcasm.
Does that make sense?
For the record, I wish I were charismatic. :harumph: Not even my brother's dog wants to play with me unless I have food or he's being ignored by everyone else. Damn him. Hahahahahaa.