Expulsion of gas from the esophagus and stomach out through the mouth. Belching is the act of expelling air from the stomach through the mouth.
Burping. Burping (also known as belching, ructus, or eructation) is the release of gas from the digestive tract (mainly esophagus and stomach) through the mouth. It is usually accompanied with a typical sound and, at times, an odor. Burping is generally caused by swallowing air when eating or drinking and subsequently expelling (or inhaling) it, so in this case the expelled gas is mainly a mixture of nitrogen and oxygen. Gas (flatus), burping, and bloating are all normal conditions. Gas is made in the stomach and intestines as your body breaks down food into energy. Gas and burping may sometimes be embarrassing. Bloating, which is a feeling of fullness in the abdomen, can make you uncomfortable. Changing what you eat and drink can sometimes cut down on gas and relieve discomfort caused by gas. Belching or burping (eructation) is the voluntary or involuntary, sometimes noisy release of air from the stomach or esophagus through the mouth. Belching or burping is also medically referred to as eructation or ructus. Essentially it is a process of releasing gas from the digestive tract through the mouth. A typical odor or sound may also accompany the process of gas release. Belching is caused by multiple factors that affect the normal process of digestion. There are many possible causes of indigestion. Some are related to lifestyle and what you eat and drink. Indigestion can also be caused by other digestive conditions. Belching, or burping, is the expulsion of gas from the esophagus and stomach out through the mouth. As the gas escapes, it produces the characteristic sound known as a burp or belch (eructation). The most common cause of belching is swallowing air. Swallowing air and belching are natural occurrences that result from eating or drinking too quickly. Chewing gum or drinking carbonated beverages can also introduce air into the stomach and cause belching. Because infants frequently swallow air when feeding, burping or belching is normal after they have been fed. The act of burping an infant helps relieve the discomfort caused by swallowed Bloating, burping and passing gas are natural and are usually caused by swallowed air or the breakdown of food through digestion. You may experience gas and gas pains only occasionally or repeatedly in a single day. When gas and gas pains interfere with your daily activities, there may be something wrong.  Symptoms. Belching is a normal process and results from swallowed air accumulating in the stomach. The air can either be belched back or can be passed out of the stomach into the small intestine and be subsequently passed as rectal gas (flatus). Bloating refers to a sense of fullness in the upper abdomen. Gas can contribute to a sense of bloating (fullness), belching, abdominal cramps, and flatulence (gas). These symptoms are usually brief and resolve once gas is released by belching or flatulence. Conditions that may cause belching include: 1  gastroesophageal reflux disease (GERD): disorder that causes acid from the stomach to flow upward into the esophagus, or food pipe. 2  gastroparesis (also called delayed gastric emptying): disorder in which the muscles in your stomach wall are weakened. Self-Treatment. If you are belching excessively or if your stomach is distended and you cannot expel the air, lying on your side usually helps. Adopting a knees-to-chest position can also be helpful. Hold the position until the gas passes. Belching is the act of expelling air from the stomach through the mouth. It usually occurs when the stomach distends (expands) due to too much swallowed air, with the belching releasing the air to reduce the distention. Other names for belching include burping and eructation. Self-Treatment. If you are belching excessively or if your stomach is distended and you cannot expel the air, lying on your side usually helps. Adopting a knees-to-chest position can also be helpful. Hold the position until the gas passes. Belching or burping is the common term associated with eructations through the mouth. Belching is a frequent occurrence after meals and consumption of certain drinks. On some occasions, repeated belching may be accompanied by bloating and a feeling of ‘fullness’ known as indigestion (dyspepsia). Contents. 
https://en.wikipedia.org/wiki/Belching http://www.webmd.com/heartburn-gerd/tc/gas-bloating-and-burping-topic-overview http://www.home-remedies-for-you.com/remedy/Belching.html http://www.healthgrades.com/symptoms/belching http://www.mayoclinic.org/diseases-conditions/gas-and-gas-pains/in-depth/gas-and-gas-pains/ART-20044739 http://patients.gi.org/topics/belching-bloating-and-flatulence/ http://www.healthline.com/symptom/burping http://www.healthline.com/symptom/burping http://www.healthitalk.com/what-is-belching-burping-passing-gas-through-the-mouth/
what is belching