It is a machine that gives charged particles high velocity.
1.) When we accelerate elements we also increase their energy. When electrons and protons collide with each other on a higher energy level there is a great chance that they --
together-- become a new element. Soon it falls apart and creates quarks, leptons or taus. Thus we can experiment with these new "bricks". Interesting fact: the velocity of an
accelerated particle can be close to the velocity of light.
2.) The particle can also react as a physical wave. We call it dual-nature. When we increase the momentum of the particle (mass times velocity) -- because of its dual-nature -
the wavelength decreases and the increase its definition.