Gastroesophageal reflux is essentially the reflux or regurgitation of stomach contents back into the food pipe or esophagus. This is a normal process that occurs in otherwise healthy children, and adults.
GERD is a condition in which the stomach acid or contents from the stomach flow back into the food pipe (esophagus). The backwash (reflux) irritates the lining of the esophagus and causes GERD. Gastroesophageal refers to the stomach and the esophagus.