Here’s the definition of traveling from the NBA Rule Book:

Section XIV-Traveling
a. A player who receives the ball while standing still may pivot, using either foot as the pivot foot.
b. A player who receives the ball while he is progressing or upon completion of a dribble, may use a two-count rhythm in coming to a stop, passing or shooting the ball.

But NBA officials rarely call traveling, especially on superstar players. Watch this clip below where Russell Westbrook takes about 5 steps before dribbling. What’s funny to me is how long it takes the ref to call it… seems like he only does it because the opposing team (and coach) are screaming for it… and how Westbrook gives the ref some side-eye after the call, like it was a bad call, when clearly he walked halfway across California.