The distinctions between ambition and arrogance are sometimes subtle, yet critical. From a distance, the two can appear to be the same. However, their results are worlds apart. Ambition is expecting the best of yourself. Arrogance is believing you are better than others.
Ambition is the desire to make a difference.
Arrogance is the belief that you're indispensable. Ambition is doing whatever it takes to accomplish what you know you deserve. Arrogance is thinking that the world owes you something, and doing what you can to take it. Ambition is disciplined and assertive. Arrogance is pushy.