Calabi-Yau manifolds are like an imaginary version of a rubber sheet that is curved and wrinkled in different directions. They are special types of shapes with a lot of properties that make them useful in lots of different fields like physics and mathematics. They have six dimensions, meaning they have length, width, and height, plus three extra directions that are harder to imagine. Even though they are made in our imaginations, they can help us understand real physical things like gravity, black holes, and energy.