If the path of the comet intersects the orbit of the Earth, we plow through that material at the same time every year. Think of it this way: imagine a racetrack, and you are driving around it. Now also imagine a long line of gnats flying across the racetrack. You would drive through that line of bugs at the same point on the racetrack every time, right? OK, replace you with the Earth, the racetrack with the Earth’s orbit, and the bugs with debris shed off a comet. Since the Earth returns to the same point in its orbit every year, if there is cometary debris there, we’ll smack into it at roughly the same calendar day every year.
This loose stuff from the comet burns up in our atmosphere, and we get a meteor shower.
Find out more about the specific new information from the Cameras for Allsky Meteor Surveillance, or CAMS. at Bad Astronomy Blog. Link