The process that makes bread rise is known as "fermentation." This biological process involves yeast, a microorganism that consumes sugars in the dough and converts them into carbon dioxide and alcohol. As the yeast ferments the sugars, it releases carbon dioxide bubbles, which become trapped in the dough, causing it to expand and rise. This not only gives bread its characteristic texture and volume but also contributes to its flavor. The duration and conditions of fermentation can vary depending on the bread recipe and desired characteristics, making it an essential technique in baking.