The leader is someone who leads a group of people, often in a more informal and less permanent capacity. They may have followers who look up to them and listen to their guidance, but they do not usually have as much power or authority as a king.

On the other hand, a king is a ruler of a country or territory who has extensive power and control over the people and resources within their domain. They usually inherit their position through a hereditary monarchy or are elected by a governing body.

Overall, the main difference between a leader and a king is the level of authority and power they possess. Kings have absolute power over their subjects, while leaders typically have a more limited influence and rely on the support and respect of their followers.