Lytro is a special camera that takes pictures in a way that's different from regular cameras. Instead of just taking one picture and making it permanent, the Lytro camera takes lots of pictures all at the same time, and each one is a little different.
Then, when you look at the picture on the camera, you can touch different parts of the picture to make them become clearer or blurrier. This means you can change what part of the picture you're focusing on, even after you've already taken the picture.
It's kind of like a magic trick where you can make parts of the picture come into focus or go out of focus, just by touching them. And it's really cool because you can play around with the picture and make it look like different things just by touching different parts of it.