The namesake objects of the Dragon Ball series are seven magical Orbs that have a number of red stars corresponding to their order in the sequence (from 1 to 7).
When all seven Dragon Balls are collected and gathered together, they allow the user to summon a powerful dragon who will grant a number of wishes (originally one, later three). Once the wish is granted, it cannot be granted again, and the balls fly off to the ends of the earth and become nothing but inert stone until a year has passed, at which point they become Dragon Balls again.
Earth's dragon balls were created by an alien from planet Namek named Kami.
