What does gravity do?

Can you explain to me in simple terms what gravity actually does? I've heard it's what keeps us grounded on Earth, but I'm curious about the mechanics behind it. Does it only affect objects with mass, or can it also impact other things? How does it work on a larger scale, like in the solar system or even the universe? And are there any exceptions to the rules of gravity, or is it a universal force that always behaves the same way? I'm eager to understand the basics of this fascinating concept.