Walking/Traveling. Taking more than 'a step and a half' without dribbling the ball is traveling. Moving your pivot foot once you've stopped dribbling is traveling.
Carrying/palming. When a player dribbles the ball with his hand too far to the side of or, sometimes, even under the ball.
Double Dribble. Dribbling the ball with both hands on the ball at the same time or picking up the dribble and then dribbling again is a double dribble.
Held ball. Occasionally, two or more opposing players will gain possession of the ball at the same time. In order to avoid a prolonged and/or violent tussle, the referee stops the action and awards the ball to one team or the other on a rotating basis.