That stands for two ways I figure you can define a character: personality and pathos.
What and why, essentially. One is the surface elements of the character, the stuff the audience will generally notice and identify the character with, which includes basic stuff like likes/dislikes, habits, etc. The other is the deeper psychological aspects of the character - motivations, the emotions they feel and that inspires their personality. Although the latter can be made surface, sometimes it can remain hidden and needs to be identifed through careful examination by the audience.
We'll take the modern Punisher as an example (SORRY I'M BEING TOO LITERARY RIGHT NOW! JESUS CHRIST!). His personality is that his goal is to go out and kill criminals for revenge. His pathos is that he is a sociopath who uses revenge as justification for being a serial killer. That's not the most subtle one, but it works as a simple example.
(Alright, a more subtle example. The protagonist of the novel Flaubert's Parrot. His personality is that he is obsessed with Gustave Flaubert. His pathos is that he is a simple-minded individual who doesn't understand why things in his life go wrong, and he is constantly looking for reasoning through Flaubert's life and literature.)
Anyway, the reason I bring this up is because I noticed last night (adding more to my 'character encyclopedia' that a friend of mine challenged me to make, and has been really helping me figure out my characters a bit better) that I was focusing quite a bit on pathos and not as much on personality. This isn't necessarily a colossal problem, but its making me rethink things. It's pretty much the opposite of how things are usually created (what and then why, rather than my why and then what). So basically, I need to figure out more elements of the character's surface-level characterization so they actually seem three-dimensional.
I am reminded of a post made on one of the blogs I read went over some elements of the personalities of the world's three most well-known superheroes (Superman, Batman, and Spider-Man), identifying their cooking/eating habits in rather bizarre detail. It was able to combine both personality and pathos perfectly - Superman likes rich foods because he can't gain weight, Batman can't cook because he's rich and gets other people to do it for him, and Spider-Man is pathologically inclined to go for cheap/average things because he has spent a good part of is life poor. Stuff like that.
What I need to do is to give some of my characters hobbies.