**Definition:**
Inheritance is a fundamental concept in object-oriented programming that allows a new class to inherit properties and behaviors (methods) from an existing class.

**Key ideas:**
- It promotes code reusability by allowing new classes to use existing code.
- The class that inherits is called the "subclass," while the class being inherited from is the "superclass."
- Subclasses can add new features or override existing ones from the superclass.
- Inheritance helps organize code into a hierarchy, making it easier to manage and understand.

**Why this topic matters in this category:**
Understanding inheritance is essential for creating efficient and maintainable code in software development.