Belching is commonly known as burping. It's your body's way of expelling excess air from your upper digestive tract. Most belching is caused by swallowing excess air. This air most often never even reaches the stomach but accumulates in the esophagus.
Though it may be unpleasant for you and those around you, burping is a completely natural way to get rid of air swallowed during eating and drinking. It's also known as belching or eructation. Burping keeps your stomach from expanding too much from swallowed air.