Character

Characters are the representations of persons in works of art. In the Fallout series, the term refers to the various inhabitants of the Wasteland. Characters can be divided into non-player characters (NPCs) and player characters (PCs).

Non-player character
A non-player character is any person in the game that the player character can interact with. They are not controlled by anyone but a set AI. So basically, a NPC is just anyone you meet in the game besides yourself.

Player character
The player character is the player's avatar in the game world. These can be designed by the player, but some of the games offer pre-designed player characters as well.