The Big Idea
All matter is composed of fundamental building blocks, called the elementary particles. These building blocks are much smaller than an atom, and so are sometimes referred to as subatomic particles. Particles interact with one another according to a set of laws based on symmetries in the universe. There are two types of particles: force particles (bosons) and matter particles (fermions). What sets them apart is an intrinsic property called 'spin'. Force particles have integer spin values (1,2,3,...) and matter particles have half integer spin values (1/2,3/2, ...). The set of particles and the laws that govern their interactions are called the Standard Model. The Standard Model is very powerful and can predict particle interactions to amazing accuracy.
The fifth of the five conservation laws is called CPT symmetry. The law states that if you reverse the spatial coordinates of a particle, change it from matter to anti-matter, and reverse it in time the new object is now indistinguishable from the original. More on the fifth conservation law in the Feynman Diagram's chapter.