Here, we probe the components of current density and show that we can gain a deeper understanding of how current flows through molecules from the MOs alone. First, we outline the formal definition of current density with an emphasis on making the equations simpler to use and easier to illustrate. Second, we show that the current density consists of simple building blocks that can be used to partition the current density into chemically intuitive subdivisions, such as σ-and π-system. Finally, we explain the current density in the three model systems outlined above where neither interatomic local currents nor transmission eigenchannels can satisfactorily explain the current density.