In countable terms the difference between ambition and conviction
is that
ambition is an object of an ardent desire while
conviction is a judgement of guilt in a court of law.
In uncountable terms the difference between ambition and conviction
is that
ambition is a personal quality similar to motivation, not necessarily tied to a single goal while
conviction is the state of being convinced.
As nouns the difference between ambition and conviction
is that
ambition is eager or inordinate desire for some object that confers distinction, as preferment, honor, superiority, political power, or literary fame; desire to distinguish one's self from other people while
conviction is a firmly held belief.
As a verb ambition
is to seek after ambitiously or eagerly; to covet.