object-oriented meaning
Build a reusable software system with modules as the center to improve the maintainability and scalability of software products.
Two basic concepts of object orientation: class and object. A class is an abstract concept, and an object refers to a concrete entity that belongs to a class.
Basic relationship between classes:
Inheritance: There is an inheritance relationship (is-a) between the class subdivided from the existing class and the original class. The inherited class (subclass) has all the properties and behaviors of the original class (parent class).
Composition: The existence of some classes must depend on other classes. This relationship is called composition. A composite class is locally composed of other classes.