Ambition is the desire for personal achievement. Ambitious persons seek to be the best at what they choose to do for attainment, power, or superiority. Ambition is also the object of this desire. A poor example of 'Ambition' could be 'to become a Confetti collector'.
People can wield their acquired power in the name of a vague or clear ideal or multiple ideals. When ambition is used to seek a clear ideal, it develops a close relationship to extremism. In the history of human kind many examples can be found of people who were extremely ambitious, for better and for worse. The notorious Greek Herostratus had the ambition to become famous by destroying the Temple of Artemis.