A basic definition of a base is a substance that has a pH greater than 7 and can accept hydrogen ions. Bases are also known as alkalis and are the opposite of acids, which have a pH lower than 7 and donate hydrogen ions. Bases are important in many different fields, including chemistry, biology, and medicine. In chemistry, bases are used to neutralize acids and to create solutions with a specific pH. In biology, bases are important for maintaining the pH balance of the body and for aiding in digestion. In medicine, bases are used to treat a variety of ailments, such as heartburn and indigestion. All in all, bases are essential for many different functions and are a vital part of the scientific world.