ELI5: Explain Like I'm 5

pluto

Pluto is a small, icy ball that used to be thought of as one of the planets in our solar system. It is now known as a "dwarf planet" which is a different kind of thing. It is located very far away from the Sun, and it is much smaller than the other planets. Because it is so far away, it is very difficult to see, and it is hard to learn much about it.