# What is the difference between the induction of a magnetic field $B$ and the magnetic field strength $H$?

I just started learning about magnetic fields by myself. In my textbook it says that the magnitude or intensity of induction of a magnetic field is equal to the amount of field lines that pass through a surface facing the direction of $$B$$. So as I understand it $$B$$ causes some magnetic objects (compass in this example) to re-oriente themselves and logically the more field lines the larger $$B$$ will be and the more this object will tend to turn itself. $$H$$ is later defined as $$B/\mu$$ effectively removing the magnetic permittivity of a vacuum giving us the "strength" of the field at that point.

Can someone tell me the difference between $$B$$ and $$H$$ as they seem to be both referencing the strength and also tell me how dividing by the permittivity of free space gives us the "strength" of the field. Also my text book sometimes calls them forces eventhough none of them at in newtons ;-;