To satisfy is to fulfill or meet a want, need, requirement, or expectation. A brilliant paper on Edgar Allan Poe might satisfy a literature class requirement, and a candy bar might satisfy a craving for chocolate.
Since there are so many things we need and want, there are lots of ways to satisfy us. Eating a sandwich will satisfy your hunger. Overhearing a conversation could satisfy your curiosity. Going to school should satisfy your desire for knowledge. In college, you'll have to take certain classes to satisfy requirements of your degree. The word comes from the Latin satisfacere, which basically means “do enough.”