🎯 1. What Are Inner/Nested Classes?

A class defined inside another class.

Java allows classes inside classes to keep related logic grouped together.

Two main types:

1️⃣ Static nested class

2️⃣ Non-static inner class

• Member inner class
• Local inner class
• Anonymous inner class

(Anonymous + local covered later when learning Lambda + OOP patterns.)

Today: static vs non-static, the core.

⭐ 2. Why Do Inner Classes Exist?

Because sometimes:

• A class is useful ONLY inside another class
• You want cleaner grouping
• You want to logically associate behaviors

Examples:

• Engine inside Car