The outer part of the sun is about 93 percent hydrogen and 6 percent helium, with one percent other elements. The "waste" product of fusion is helium, which is a stable and useful element. Scientists have spent decades and billions of dollars trying to harness this process, but the extreme temps are a problem. There is a possibility of "cold" fusion, but that is not possible yet.
Inside the sun, an estimated 600 million tons of hydrogen undergo fusion each second. About 4 million tons of this matter is converted into energy. This energy radiates out into space and the earth gets a very small part of it in the form of white light which is a combination of red, orange, yellow, green, blue, indigo and violet waves, infrared (heat) waves, ultraviolet (sun tan) waves and others. Our atmosphere, magnetic field and ozone layers protect us from the harmful effects of some of these rays. The ozone is a three oxygen molecule rather than the normal two. Ozone has a sweet smell that is present around electrical sparking or lightning.
As the sun looses matter in this process, this means that there is mass, thus less gravity to control the size of the sun and it will eventually expand and engulf the planets in the solar system and then collapse back on itself.