Space and Time
Mass Appeal
Imagine that this page is actually a trampoline. Any object would sink into the surface. The more massive something is, the more it sinks in. This is why the elephant sinks into the page more than the ant!

Now, say that the trampoline represents space and time, and the elephant represents the Sun. Just like the elephant "bends" the trampoline, the Sun's mass causes space and time to bend! Got it? Now you're thinking like Einstein!