Via Rock, Paper, Shotgun I found this on characters of roleplaying games (RPGs): RPG Style: Analyzing the Structure of RPG Protagonists.
A player character:
For as much as a role-playing game Human Revolution is, it’s difficult to truly play it as a role-playing game. Every bit of dialogue that grates with my ideal is jarring, and snaps me back out of the magical game-world where player and character are the same. I found myself dreading dialogue options: Would choosing this option make Jensen look like some faceless arm of a crime syndicate instead of a person who merely weighs options to find the most logical one? Should I find a bag of puppies for him to oppress?
The problem is that Jensen is not me. He can’t be the character I envision in my head, no matter how much I try. He is his own character, an entity wholly separate from me. I am just the invisible hand telling him which baddies to shoot and what to say in conversation.
as opposed to a player avatar:
I’ve played an uncomfortable amount of Skyrim. My character, a Khajiit shadowmage, was my companion throughout the fifty-so hours of trekking through Skyrim’s frozen tundras. But without me, the character is meaningless. He’s only tangentially related to the plot, and that’s only because the player is the most important person in the game. He can’t exist outside of my influence, he has no personality, no skills besides what I’ve chosen. I am him and he is I. That’s as simple as it gets.
This is the idea of a player avatar.
The player avatar is nothing without the player. Without you, the avatar cannot exist. The avatar works in a narrative sense by allowing you to insert yourself in the story of the game without breaking the flow.
(Links to the articles at Wikipedia added by myself).
The blog post is worth reading in full (provided you are interested in RPGs at all, that is).