Static Properties and Methods
Use static members for class-level state and utilities (carefully).
Use static members for class-level state and utilities (carefully).
Call the same method name on different objects and get type-specific behavior.
Learn common inheritance structures: single, multilevel, hierarchical, and multiple.
Build inheritance chains where a child becomes a parent for another class.
Create multiple specialized subclasses from one shared base class.
Understand multiple inheritance and how PHP approximates it with interfaces and traits.
Add behavior to classes with methods — functions that operate on object state.