The particles which form the building blocks of atoms and those which carry energy.
Originally, the name given to protons, neutrons and electrons before it was discovered that protons and neutrons had substructure (quarks).
These are now known as fundamental particles for the six types of quarks and the six leptons and their antiparticles, which have no known substructure. Gluons, photons and W and Z bosons are also fundamental particles. All other particles are composite: made from combinations of fundamental particles.
Subjects: Nuclear and Particle Physics