World Gold Demand - Four major sources of demand for gold

1) Jewelry fabrication

2) Industrial applications

3) Governments and central banks

4) Private investors

1) Jewelry fabrication: The largest source of demand is the jewelry industry. In recent years, demand from the jewelry industry alone has exceeded Western mine production. This shortfall has been bridged by supplies from reclaimed jewelry and other industrial scrap, as well as the release of official sector reserves. Gold's workability, unique beauty, and universal appeal make this rare precious metal the favorite of jewelers all over the world.

2) Industrial applications: Besides jewelry, gold has many applications in a variety of industries including aerospace, medicine, electronics and dentistry. The electronics industry needs gold for the manufacture of computers, telephones, televisions, and other equipment. Gold's unique properties provide superior electrical conducting qualities and corrosion resistance, which are required in the manufacture of sophisticated electronic circuitry. In dentistry, gold alloys are popular because they are highly resistant to corrosion and tarnish. For this reason gold alloys are used for crowns, bridges, gold inlays, and partial dentures. 

3) Governments and central banks: The third source of gold demand is governments and central banks that buy gold to increase their official reserves.

4) Private investors: Finally, there are private investors. Depending upon market circumstances, the investment component of demand can vary substantially from year to year.

Article source: Compliments of  the World Gold Council