What is the role of the esophagus?

It is a tube that connects the pharynx (throat) with the stomach. It passes down the neck, pierces the diaphragm just to the left of the midline, and joins the cardiac (upper) end of the stomach. When a person swallows, the muscular walls of the esophagus contract to push food down into the stomach. Glands in the lining of the esophagus produce mucus, which keeps the passageway moist and facilitates swallowing.

The main function of the esophagus is a tube that connects our mouth to the stomach. it is also known as the gullet. The Word esophagus comes from a greek Word which means to carry what is eaten.
The esophagus is your food tube. Your trachea is our tube for air.