A distillate made entirely from a particular product – usually a fruit and usually not aged although it can be. Example a kirshwasser (cherry water) is an eau de vie made from fermented cherries and distilled. An eau de vie is a particular form of brandy.
Brandies are a wider category which can include grape distillates that are flavored by another product. An eau de vie is strictly made from one type of product ( again such as cherries,pears, plums, raspberries, etc.,)