Well consider the classic example of class Car, It has few attributes like tyres, makeYear, color.
public class Car {
private int tyres;
private String makeYear;
private String color;
public Car(String color, int tyres, String makeYear) {
this.tyres = tyres;
this.makeYear = makeYear;
this.color = color;
}
//Getters and Setters
}
Now there can be multiple instances of car each depicting certain state, say for example, Car1 is red in color, 4 types and 2012 as makeYear and Car2 is blue in color, 5 tyres and 2000 as makeYear. So using instances we can give the states to this Car class.
Something like:
Car car1 = new Car ("red", 4, "2012");
Car car2 = new Car ("blue", 5, "2000");