Typically Brandy and Cognac are categorised as VS, VSOP, XO and XXO aged 2, 6, 10 and 14 years respectively. During aging, the Brandy develops a more complex and deeper flavour profile, and again, in general, older Brandy develops a smoother palate.
Brandy is a spirit made from fruit based wine, usually grape, but other fruits like pears, cherries or apples can be used. Cognac is a French brandy made only in specific French locations.