solar radiation:  The Sun emits energy in the form of charged particles and electromagnetic radiation.  Solar radiation is most familiar in the form of heat (infrared radiation), light (visible spectrum), and the invisible rays that cause sunburn (ultraviolet radiation).  The Sun also emits radio waves, microwaves, X-rays, and gamma rays.  The many different forms of energy given off by the Sun are called solar radiation.

solar system:  The Sun, the nine known planets, their moons, and all  the asteroids, comets, meteoroids, and other material that orbit the Sun are called the solar system. The solar system is made up of the Sun and all the objects that orbit the Sun.  Everything in the solar system is affected by the Sun's gravitational pull.