H can be understood as the effort you put into magnetic field generation, and B is the outcome result caused by field H, which can be stronger depending on what is affected by the magnetic field. Their difference is given by multiplication factor µ, called magnetic permeability and B = µH. The relation between B and H is different in SI and CGS unit systems, where H has its unit 1 A/m in SI or 1 Oersted (Oe) in CGS and B has its unit 1 Tesla (T) in SI or 1 Gauss (G) in CGS.