Superconductors are like magical materials that can carry electricity without losing any of it. Imagine you have a slide at the playground, and when you go down, you lose some energy because of friction with the slide. In most materials, electricity loses a little bit of energy as it moves, just like you lose speed on the slide.
But in a superconductor, it's like a super-smooth slide where you can go down without slowing down at all! The electricity flows through it perfectly, without losing any energy. However, these "magical" materials only work when they’re really, really cold, like winter snow cold or even colder!