Matter or ‘stuff’ we encounter in our day to day experience such as gases, liquids or gases is composed in different arrangements of atoms. Inside these atoms are protons, neutrons and electrons. The protons and neutrons are made of smaller subatomic particles called quarks.
All these building blocks: atoms, protons, neutrons, electrons and quarks can be referred to as matter.
If you look in a mirror you see a version of yourself that looks different yet the same. The slight difference is that the image you see in a mirror has been laterally inverted so your mirror image will look slightly different from a photo because our faces are not exactly symmetrical. The differences between matter and antimatter is similar. Most properties are the same, but some will be reversed.
For every matter particle there is a corresponding antimatter particle. The antimatter particle is the same in most ways but if the matter particle is positively charged the antimatter particle will be negatively charged. If the particle is made of quarks like a proton and neutron then the antiproton or antineutron will be made of antiquarks.
If an antimatter particle meets its partner matter particle such as a proton and antiproton, then they will annihilate or destroy each other and release energy.
Antimatter could be used to make a bomb much more powerful than a nuclear bomb. As little as 1g of antimatter could produce a bomb that easily equals a thermonuclear bomb. We don’t need to be alarmed because it is very difficult to create and store it and all antimatter made in the last 20 years would probably just release enough energy to make a cup of tea.
Antimatter is closer than we think. PET scanners in hospitals use positrons (antielectrons) to form images of the body. The humble banana is also a positron emitter.
As such small amounts of antimatter can release a lot of energy it is often viewed as a popular fuel for vehicles of the future but as previously mentioned it is so very difficult to produce and store that this isn’t going to happen anytime soon!