what is instance
Basically an instance is an object. Think of it like this: When you buy a car, you got an instance of a Car Blue print called Class in programming language. so your car has some properties like a color... My car would be another instance of the same blue print of the car you bought and my favourite color is silver. Hope this help.
Think of it as a real PRODUCT (with eg color) of an hand sketch car (black and white).