The standard model is the name given in the 1970s to a theory of fundamental particles and how they interact. It incorporated all that was known about subatomic particles at the time and predicted the existence of additional particles as well.
There are seventeen named particles in the standard model, organized into the chart shown below. The last particles discovered were the W and Z bosons in 1983, the top quark in 1995, the tau neutrino in 2000, and the Higgs boson in 2012.
Fundamental fermions, or the mediators of interactions, called bosons. There are twelve named fermions and five named bosons in the standard model.