What is the difference between a comet, an asteroid and a meteor?

Comets are asteroid like objects made of rock, ices and organic compounds. When they get close to the Sun, gases and dust are driven off into space and forming a coma and tail that can be millions of miles long. When they return to the outer Solar System, they become inactive and resume their asteroid like appearance through a telescope. Most comets come from the Kuiper Belt which begins around Neptune's orbit or the Oort Cloud, which extends at least one light year from the Sun in all directions. Asteroids are made of rock, metal and sometimes organic compounds as well, but little or no ice. Unlike comets, most asteroids stay between the orbits of Mars and Jupiter, with the remainder wandering through the inner Solar System. When they get near the Sun, they do not form a tail and remain star like through a telescope. A meteor is simply the trail of ionized gases left behind when a particle from a comet or asteroid hits our atmosphere and burns up 50 miles or more above the ground. If however, part of a meteoroid, or chunk of an asteroid or comet reaches the ground, it becomes a meteorite.