Dental caries, commonly known as tooth decay, is a disease that affects the hard tissues of the teeth. It occurs when bacteria in the mouth produce acids that erode the tooth enamel, leading to cavities. Factors such as poor oral hygiene, sugary diets, and lack of fluoride can increase the risk of developing dental caries. Preventing dental caries involves maintaining good oral hygiene practices, such as regular brushing and flossing, and visiting a dentist for check-ups. Additionally, reducing the intake of sugary foods and drinks and using fluoride toothpaste can help protect teeth from decay.