These planets move around the sun in a circle called an orbit. Some planets have many different moons, and some have rings around them made of rock and bits of ice. Some of them have ancient volcanoes and at least one has active volcanoes. Looking up at the night sky, the other planets look like bright stars. When you look through binoculars or a small telescope though, real stars just look brighter.
Planets look like disks, or tiny balls.
Also, while star patterns or constellations stay the same as they move across the sky, the planets change their position. Later, after telescopes were invented, three other planets were noticed, bringing the total to nine if we include Earth. There are basically two types of planets. Mercury is the closest to the Sun and is also the smallest of the inner-planets. It has no real atmosphere.