What is an object? It might seem obvious. But it's not as obvious as you might think.

Click Start, and watch the "object" move across the screen. It seems pretty clear that this is an object, doesn't it?

But in fact, what appears to be an object is not really an object at all. All that is happening is that little squares on the screen are turning "on" and "off," following a set of simple rules. And those rules say nothing at all about objects and nothing at all about direction.