interface in java
In many cases, it is more important to know what an object can do,instead of
how it does what it does. This is a reason why interfaces are commonly used for
declaring a type of variable.
interface : DrawingTool : a tool can draw
interface DrawingTool {
void draw(Curve curve);
}
DrawingTool pencil = new Pencil();
DrawingTool brush = new Brush();
Both Pencil and brush class should implement draw method