Basically Alphas can impregnate regardless of their anatomy (but not other alphas), omegas can get impregnated regardless of their anatomy, and betas are just normal people. That’s sort of the main gist, but it’s not necessarily about impregnation always. Typically there’s stuff like heat and rut cycles, knotting, pheromones, marking mates, and some others involved. That’s the one paragraph intro.