What is "yeast"?

Yeast is a type of fungus commonly used in food preparation, especially in baking. It serves as a leavening agent, aiding in the fermentation process by converting sugar into carbon dioxide, which causes the dough to rise. Yeast adds a distinct flavor and aroma to bread, pastries, and other baked goods. It plays a crucial role in creating light, airy textures and contributing to the overall taste and structure of the final product.