A planet is a celestial body that is in orbit around the Sun, has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium shape, and has cleared the neighbourhood around its orbit.
The Sun is a yellow dwarf star, a hot ball of glowing gases at the heart of our solar system. Its gravity holds the solar system together
A asteroid is a small rocky body orbiting the sun
A comet is an icy, small Solar System body that, when passing close to the Sun, warms and begins to release gases, a process called outgassing.
A moon isa celestial body that makes an orbit around a planet