In physics, antimatter is simply the “opposite” of matter. Antimatter particles have the same mass as their counterparts but with other properties flipped; for example, protons in matter have a positive charge while antiprotons are negative. Antimatter can be made in a lab using high-energy particle collisions, but these events almost always create equal parts of both antimatter and matter and, when two opposing particles come in contact with one another, both are destroyed in a powerful wave of pure energy.
Source:
https://phys.org/news/2019-09-neutrinos-antimatter.html