A chocolate ganache is made using a mixture of cream and chocolate pieces, in which the cream is heated first, added to the chocolate, and allowed to rest while the chocolate melts. It’s important to allow the heated cream to sit in the chocolate pieces for a while in order for the chocolate to melt and mix in consistently. Then the ganache is cooled down to create a thicker consistency that creates wonderful coverings for cakes and other desserts. It is an important piece of a baker's repertoire and is used often for maximum chocolate deliciousness. Source