Generate means produce or create. A good stock pick might generate cash, and a good idea might generate the basis for an Oscar-winning film.
Generate and the closely related word generation both come from the Latin word genus, which means "stock or race." Its root, in turn, is the Proto-Indo-European gen-, "to produce, give birth, or beget." Let's say you have two siblings. In that case, your parents' marriage has generated three children. In a hydroelectric power plant, water generates power. And you can get a paper route or babysit if you're looking to generate a little income.