The auxiliary field, H is defined from the magnetic field B, the magnetization M and the
permeability of free space μ0.
Confusion sometimes arises because the H field was named the magnetic field or magnetic field
intensity in the past, while B was denoted as the magnetic flux density or magnetic induction.
Similar to Thermodynamics, where we can talk about macroscopic phenomenon and solve
problems without dealing with microscopic properties, the H field is a macroscopic field like the
electric displacement D.
References
[1] Magnetic field, Wikipedia
[2] Jackson, D. ”Classical Electrodynamics”, John Wiley and Sons, Inc., 1975.
[3] Griffiths, D. ”Introduction to Electrodynamics”, Prentice-Hall, Inc., 1999.
