To some people, France is the home of bread. The baguette or French stick stands in baskets in bakeries the world over, and the heavier, homelier pain de campagne is thought the touchstone of hearty goodness.
There are two traditions at work here. Pain de campagne and many of the older breads are made with a leaven or sourdough (though it is never as sour as a German rye bread, for example) while the more modern types, of which the baguette is the most famous, depend on a long fermentation based on yeast.