A five-pointed star marking something as favoured or rated.
A five-pointed star marks something as favoured, or forms part of a rating scale. Which of the two it means has to be read from context, because the same glyph serves both.
A star of five points drawn as a single continuous outline, one point directed upward and two resting toward the base.
Both save something for later, with no agreed division between them.
A heart and a star both express approval; which one a service uses is a product decision, and users read them as broadly the same act.