Dependency inversion principle

The Dependency Inversion Principle is about making sure your code is flexible and easy to change. It says that you should make sure the smaller parts of your code - like a class or a function - don't rely on each other. Instead, they rely on something they have in common - like an interface, or a shared function - which all other classes know how to use. That way, when you need to change one of the classes, it doesn't affect the others.