Magnetic fields are found everywhere in the cosmic Universe. Theyhave been known to exist on the Earth for centuries. They weredetected in the Sun, measured in situ in the planets, observed instars, galaxies and clusters of galaxies. Magnetic fields areresponsible for many observed effects like radio continuum emission,jets, beamed emission in pulsars, star formation, etc. Possibly thewhole universe is intimately governed by the presence of magneticfields. This review will summarize the observational results anddiscuss the present interpretation for the origin of the magneticfields.