“If antimatter and matter make contact, both are destroyed instantly. Physicists call the process ‘annihilation.” -Dan Brown
Antimatter is the counterpart to matter: it exists with the same mass, opposite charge, and if ever the two should touch, they annihilate away into pure energy via Einstein’s E = mc^2. But there are a great many properties of antimatter that we haven’t yet measured due to how much energy it takes to create it and how difficult it is to contain.
As we continue to make advances on this front, it’s important to keep in mind why we do it: antimatter must be fundamentally different from matter in some vital ways to create a Universe that’s filled with matter and not antimatter today. We’ve uncovered very few ways that these particles and antiparticles are different, and they’re so far insufficient to explain why our Universe is the way we observe it to be.