First the 'M' words that often cause confusion:

Meteoroid - a bit of rock moving through space.

Meteor - a glowing trail in the sky created by a meteoroid entering the atmosphere.

Meteorite - a piece of a meteoroid that has survives entry and lands on Earth.

And now some other words that come up when you find out about space rocks:

Asteroid - a large irregular rock orbiting the Sun. Most are found between the orbits of Mars and Jupiter.

Atmosphere - there is no real edge of the atmosphere, it just gets thinner until it meets the solar wind at 10,000km (which also happens to be the distance between the North pole and the Equator). But 75% of the atmosphere is within 11km of the surface.

Fireball - a particularly large meteor. Some are even visible in the daytime.

Moon - a large spherical body orbiting a planet. Some 'moons' are really captured asteroids - e.g. Mars' Phobos and Deimos. The name of our Moon is really 'Luna' (and our star is' Sol')

Orbit - the curved path of an object caused by its gravitational attraction to another object. Gravity increases as distance decreases, so objects obit faster when they are closer together. The Earth orbits the Sun at 30km per second, completing a 1.5 million km orbital journey once a year.

Planet - a large spherical body orbiting the Sun.

Space - officially starts at an altitude of 100km but the air particles here will soon slow a satellite and bring it down. Meteorites start to heat up at an altitude of 120km.