Gastric acid, also known as stomach acid, is a digestive fluid produced in the stomach. This acid plays a vital role in the breakdown of food and decomposition of pathogenic microorganisms. However, there are several synonyms for gastric acid, such as hydrochloric acid, gastric juice, and digestive acid. Hydrochloric acid is the primary component of gastric acid, and it helps convert pepsinogen to pepsin, an enzyme that aids in protein digestion. Gastric juice is the collective mixture of stomach secretions, including hydrochloric acid and enzymes, that breaks down food in the stomach. Digestive acid is a generic term for all stomach acids and enzymes that aid digestion.