The main ingredient in beer is malted barley, which undergoes a brewing process that includes mashing, boiling, fermenting, and conditioning. Malted barley provides the sugars necessary for fermentation, during which yeast converts these sugars into alcohol and carbon dioxide. Other essential ingredients typically include hops, which add bitterness and aroma, and water, which serves as the primary solvent. Additional grains, such as wheat or corn, can be used to create specific beer styles. The combination of these ingredients results in a wide variety of flavors, aromas, and styles, making beer one of the most diverse alcoholic beverages worldwide.