Explore java interface and abstract class, then answer the below questions.

$1.$ What is the key difference between an interface and an abstract class?

$2.$ When would you prefer using an interface over an abstract class, and vice versa?

$3.$ How does the use of multiple inheritance differ between interfaces and abstract classes?

$4.$ Write Java code to demonstrate your answer, use comments to explain how each part demonstrates the characteristics of interfaces and abstract classes. Be a bit original pls$.$