One of the primary goals in modern physics is to answer the question “What is the Universe made of?” Often that question reduces to “What is matter and what holds it together?” This continues the line of investigation started by Democritus, Dalton and Rutherford.
Modern physics speaks of fundamental building blocks of Nature, where fundamental takes on a reductionist meaning of simple and structureless. Many of the particles we have discussed so far appear simple in their properties. All electrons have the exact same characteristics (mass, charge, etc.), so we call an electron fundamental because they are all non-unique.
The search for the origin of matter means the understanding of elementary particles. And with the advent of holism, the understanding of elementary particles requires an understanding of not only their characteristics, but how they interact and relate to other particles and forces of Nature, the field of physics called particle physics.
The study of particles is also a story of advanced technology begins with the search for the primary constituent. More than 200 subatomic particles have been discovered so far, all detected in sophisticated particle accelerators. However, most are not fundamental, most are composed of other, simpler particles. For example, Rutherford showed that the atom was composed of a nucleus and orbiting electrons. Later physicists showed that the nucleus was composed of neutrons and protons. More recent work has shown that protons and neutrons are composed of quarks.