An antiproton is a subatomic particle that is the antimatter counterpart of a proton. While a proton has a positive electric charge, an antiproton carries a negative charge. Antiprotons are produced in high-energy particle collisions, such as those occurring in particle accelerators like the Large Hadron Collider. When an antiproton encounters a proton, they can annihilate each other, resulting in the release of energy in the form of gamma rays. This annihilation process is a key area of study in particle physics and helps scientists understand the fundamental forces and particles that make up the universe.