In graphic novels, the thought bubble is used to show internal dialogue. The term that is more widely used is <em>internal monologue</em>. In literature, a dialogue is a conversation between two or more characters, and a monologue is a speech presented by one character in order to show their thoughts. When those thoughts remain inside a character's head, we have an internal monologue/dialogue. In graphic novels, we can get insight into those thoughts thanks to thought bubbles.
