I'm desperate, trying to solve an N-Channel MOSFET problem

NMOS = N-Channel MOSFET (Metal oxide semiconductor field effect transistor)
PMOS = P-Channel MOSFET

NPN transistor = NPN BJT (Bipolar junction transistor)
PNP transistor = PNP BJT

MOSFET is also a type of transistor, but when it is simply called a "transistor", it usually refers to BJT.