Concept is the cognition of human brain to the essential characteristics of objective things,the essential characteristics of things determine the nature of things and distinguish one thing from others.Concepts can be divided into concrete concepts and abstract concepts according to the abstraction and generalization of their attributes. The concept formed according to the attribute is called concrete concept,The concept formed according to the intrinsic properties of things is called abstract concept.
an abstract concept?
Bananas and watermelons are fruits, cabbages and potatoes are vegetables.