What is magnetostatic energy? Sometimes, it becomes extremely difficult to visualise the physical significance of a given term only by its definition. I have been facing trouble understanding what exactly magnetostatic energy is? 
I came across this term while learning the domain theory... Can somebody please explain in layman's terms what magnetostatic energy is?
 A: Magnetostatic energy is the energy stored in a static magnetic field, just like electrostatic energy is the energy stored in a static electric field.
The energy density (energy per unit volume) of a magnetic field is $\vec{B}^2/8\pi$. The energy density of an electric field is $\vec{E}^2/8\pi$. (I’m using Gaussian units.)
In introductory electromagnetism courses, electrostatic energy is often described as the work required to assemble the charges that produce the electric field. Since there are no magnetic charges, there is not an exact analogy for magnetostatic energy. However, you can consider the sources that do produce magnetic fields, and the work required to assemble them. For example, the magnetic energy of interaction of two parallel infinite wires with equal current flowing in opposite directions (which repel each other) is the work required to bring them together from infinity.
When you feel the warmth of sunlight on your skin, the energy being transferred to your skin comes half from the magnetic field of the sunlight and half from the electric field. Of course, in this case the fields are oscillatory rather than static. 
