What are stars and constellations?

Assuming you meant

• star (a plane figure with a number of triangular points arrayed within an imaginary circle; often used as an emblem) and asterism, a pattern of stars seen in Earth's sky which is not an official constellation

Did you mean?

• star (a plane figure with a number of triangular points arrayed within an imaginary circle; often used as an emblem) and constellation (a collection of something with a specific structure)