If you watch a lot of the popular sitcom, 'The Big Bang Theory' or if you're a big science nerd like me, you've probably heard about these terms, but failed to understand. Let's see if I can be of any help :)
So, lets start with the most popular physics equation, E=mc².It basically says that mass is concentrated energy and mass and energy are interchangeable, kind of like two currencies but with a huge exchange rate. 90 trillion joules of energy is equivalent to 1g of standard mass. If we concentrate huge amounts of energy in a tiny space, new particles will come into existence. If we look closer we see that these particles always come in pairs, like twins. That's because particles( each and every one of them) always have their counterpart an 'antiparticle' and these are always produced in exactly equal amounts (1:1 ratio). This might sound like science fiction, but it's actually true and is the daily life at particle accelerators, CERN LHC (We'll discuss that soon).
In the collisions between two protons between CERN's LHC, billions of particles and antiparticles are produced every second. Consider for example the electron. It has a very small mass ( in physics we call it infinitely small) and a negative charge. It's anti particle, the positron has exactly the same mass but an opposite positive charge. But apart from the opposite charges, both particles are identical and perfectly stable. And the same is true for the heavy cousins, the proton and the anti-proton. Therefore, scientists are convinced that a world made of antimatter would look, feel and smell just like our world. In this anti-world, we might find anti-water, anti-gold, anti-food and maybe anti-you & me!
Now imagine a matter and an antimatter particle are brought together. These two apparently if are in contact, would completely disappear into a big flash of energy, equivalent to an atomic bomb! Because combining matter and antimatter would create so much energy that it can run future spaceships like in Star Wars, cause energy content of antimatter is a billion times more than the conventional fuel. The energy of 1g of antimatter would be enough to put a rocket in our orbit. So why not use antimatter in energy production? Well, antimatter isn't just sitting around. We have to make antimatter before we can combust it.