The mass term for the type-I seesaw is given by $$\mathcal{L}_{mass}=-m_D\overline{\nu_L}N_R+M_R\overline{(N_R)^c}N_R+h.c.$$ where the right-chiral fields $N_R$ are electroweak singlets. Since they do not have any Standard model interactions, they are called sterile. On the other hand, $\nu_L$ fields are not sterile.
Now I've found two more terms in the literature. Light neutrinos and active neutrinos. When we diagonalize the $6\times 6$ neutrino mass matrix $M_\nu=\begin{pmatrix}0 & m_D\\m_D^T & M_R\end{pmatrix}$ resulting from the Lagrangian above, we get, 3 light Majorana neutrinos and three heavy Majorana neutrinos (both are linear combinations of $\nu_L$ and $N_R$).
My question is, among $\nu_L$, the 3 light Majorana neutrinos or the 3 heavy Majorana neutrinos what are referred to as active neutrinos? And why?
In wikipedia, $\nu_L$ of the Standard Model are referred to as active which I think is in contradiction with the link above.