What is a comet?
Comets are also formed of material left from the formation of the solar system. However, unlike an asteroid, comets aren't just rocky material. They're additionally composed of ice and gas.
Comets also orbit the sun, though not like an asteroid. In his description of meteor showers, Gregory A. Lyzenga, a physics professor at Harvey Mudd College, writes that the orbit of a comet is more of an "elongated ellipses." As a comet moves toward the sun, the ice and dust inside the comet vaporize to form the tail. Interestingly, the tail always points away from the sun. So, the tail isn't necessarily behind the comet. It can also be beside or in front of the comet's path.
Comets leave a trail of dust and debris in their wake. Meteor showers can happen when the Earth's orbit intersects the orbital path of a comet. The dust left by the comet falls into the Earth's atmosphere and becomes the bright meteors you've maybe looked up at on a summer night.