AA grade is a grade name of coffee bean currency: the grade of currency coffee beans is generally AA, A, B and C, which mainly refers to the size of coffee beans.
Coffee bean: refers to the fruit of a plant used to make coffee. Broadly speaking, there are two kinds of coffee beans in the world, Arabica beans and Robusta beans. The fruit of coffee consists of two oval seeds. One side connected to each other is a flat joint, called lentil. But there is also a round seed called round bean, which has no different taste.