is this basic fact understood?
Yes. This is because the exchange energy goes down by having spins align. But having spins aligned generally results in an increase in kinetic energy. That's true for any material. But for iron, the increase in kinetic energy is smaller than the decrease in exchange energy. This is because the bands for the 3d electrons in iron are narrow. They are narrow because 3d orbitals are fairly localized and 3d orbitals on neighboring atoms don't have much overlap.
You can get more or less sophisticated and/or convoluted answers from more or less sophisticated models.
First, we must know the meaning of the term "FERROMAGNETIC"
Ferromagnetic is the phenomenon exhibited by substances, such as iron, that have relative permeabilities much greater than unity and increasing magnetization with applied magnetizing field. Certain of these substances retain their magnetization in the absence of the applied field. The effect is caused by the alignment of electron spin in regions called domains
Separate names with a comma.