Key difference: A meteor is the flash of light that follows a piece of interplanetary debris as it enters our atmosphere. We often refer to meteor as a falling star or shooting star. A meteoroid is any debris in the Solar System. The size of a meteoroid can range from the size of a grain of sand to a boulder sized particle weighing 220 lbs (100 kgs).

A meteor is the flash of light that follows a piece of interplanetary debris as it enters our atmosphere. Meteor is not the debris itself, but the flash of light caused by the debris. We often refer to meteor as a falling star or shooting star.

The meteor, i.e. flash of light, is caused as the debris heats up due to the incandescence by the friction of the atmosphere. Many meteors appearing seconds or minutes apart, and appearing to originate from the same fixed point in the sky, are called a meteor shower.

Sometimes the falling debris is an asteroid that has been knocked off course and is pulled in by the earth’s gravitational pull. However, mostly the object is a meteoroid.

A meteoroid is any debris in the Solar System. The size of a meteoroid can range from the size of a grain of sand to a boulder sized particle weighing 220 lbs (100 kgs). The larger meteoroids are often termed as asteroids. The rule of thumb is that anything smaller than a kilometer is termed as a meteoroid, while anything bigger is an asteroid. These meteoroids can come from various sources, such as other planets, their moons, our moon, other asteroids, etc.

When these meteoroids enter the earth’s atmosphere they cause a meteor, i.e. a trail of light, which we refer to as a falling or shooting star. Usually, the meteoroid is small enough that it gets burned up in the process. If the meteoroid survives and lands on the surface of the Earth, or parts of it do, they are termed as meteorites.

Hence, the main difference between meteor and meteoroid, is the fact that meteoroid is the piece of rock entering our atmosphere, while a meteor is the flash of light and burning debris following it. 

Image Courtesy: mikesastrophotos.com, meteoriteassociationofgeorgia.org