Both words have similiar meanings but should be used according to the context. Confidence - A belief ( of certainity, positive attitude, ability to accomplish) For example , Confidence in your ability ( being able to do the job ) Conviction - A Belief ( as outcome of persuasion,opinion, thought ) For example, conviction in your voice ( ability to convince/persuade)

Conviction- a belief. "I have a conviction that I should help the poor." Confidence- belief in yourself; a belief that you can do something. "I have confidence that I can run a marathon"