For instance, electrical engineering is the study of the practical application of electromagnetism.
A key difference between physics and mathematics is that because physics is ultimately concerned with descriptions of the material world, it tests its theories by observations (called experiments), whereas mathematics is concerned with abstract logical patterns not limited by those observed in the real world (because the real world is limited in the number of dimensions and in many other ways it does not have to correspond to richer mathematical structures). For instance, electrical engineering is the study of the practical application of electromagnetism.