Magnetic Flux
Magnetic flux is the quantity of magnetic force lines and is analogous to current in an electric circuit. Flux is obtained by integrating the flux density over the surface area. The symbol for the magnetic flux is φ. The units are the weber [Wb] for the SI system and the Maxwell [Mx] for CGS units. 1 [Wb] = 108 [Mx].
Magnetic Flux Density
Magnetic flux density is the amount of magnetic flux per unit surface area. The units are the tesla [T] for SI units and the Gauss [G] for CGS units. The symbol for the magnetic flux density is B. The magnetic flux density within a magnetic body is the sum of the external magnetic field H and the magnetic body magnetic polarization J and in SI units is expressed as B=μ0H+J. 1 [T] = 104 [G].
Magnetic Field
Magnetic field is the force operating on the magnetic charge. The symbol for the magnetic field is H and the units are the ampere/meter [A/m] for SI units and the oersted [Oe] for CGS units where 1 [A/m] = 4π•10-3 [Oe]. The Earth itself posses a magnetic field referred to as geomagnetism.