Here's the breakdown:

* Electrons have an intrinsic magnetic dipole moment: Electrons behave like tiny magnets, possessing a magnetic dipole moment due to their spin and orbital motion. This moment acts like a tiny bar magnet with a north and south pole.

* Magnetic domains: In a ferromagnetic material (like iron), the electrons' magnetic moments tend to align within small regions called magnetic domains. These domains are like mini-magnets within the larger material.

* External magnetic field: When an external magnetic field is applied, it interacts with the magnetic moments of the domains. The domains align themselves with the external field, causing the material to become magnetized.

* Permanent magnets: In permanent magnets, the domains remain aligned even after the external field is removed. This is because the magnetic moments within the domains are strongly coupled, making them resistant to demagnetization.

So, it's not a single external force that aligns electrons; it's the interplay between the electron's intrinsic magnetic moment and the external magnetic field. This interaction leads to the alignment of domains, which in turn gives rise to the macroscopic magnetic properties of the material.