Hi.
If you are asking how the Sun's magnetic fields affect the Earth - they are the causes of solar activity, which can affect out technologies (power systems, spacecraft, communications) in various ways and also cause the Northern and Southern lights.
See http://www.solarweek.org/...bid/181/Default.aspx for more information.
A
lot of how the Sun's magnetic field affects us is tied into Earth's
magnetic field. Earth's magnetic field protects us from some of the
effects of solar activity. We also use Earth's magnetic field for
navigation. Other "terrestrial" planets (Mercury, Venus, and Mars) have
smaller magnetic fields than Earth. this may have affected their
evolution. That is one of the things the MAVEN mission to Mars is studying
Best,
Terry