The most efficient classification scheme is a succession of orthogonal binary dichotomies in which (if possible) roughly half the items to be classified go on each side of every successive distinction. These may be drawn as "Venn diagrams" in which a circle (representing everything) has a line drawn through the middle.
The first distinction does not even come close to splitting up all the "elementary" particles into two equal groups, but at least it is unequivocal. This is the question of whether the particle is strongly interacting or not. If it is affected by the strong interaction, it is called a hadron. If not, it is called a lepton. [Both of these have Greek roots. Look them up if you're curious.]