There are distinct bread types, depending on the rising agent: yeast-raised bread, poolish bread, and leavened bread.
Although it doesn't have the full flavour of a leavened bread, poolish gives a bread with more flavour than one just using yeast.
.[Translator's note: the term poolish is more common in French baking than in English. For more information see the Pre-ferment, article on Wikipedia.].
Example: "Prepare a poolish by mixing the water, flour, yeast and a teaspoon of sugar."