Everything is made up of fundamental entities. The most fundamental entity of a physical interaction or quantity is called a quantum. Every interaction that exists in nature has its own name for its respective quantum.
For instance, let us consider light. Light is composed of particles or small packets of energy analogous to matter, composed of packets of particles – atoms (though atom is not fundamental). This packet of energy is called a quantum of energy and coined a name, photon. Also, quanta is the plural of quantum. Quanta of energy refers to a group of photons.
Likewise, quantum of strong interaction is called gluon and quantum of weak interaction are called W and Z bosons. However, the understanding of these interaction is beyond the scope of this explanation.