A burp is nothing but gas. When we eat or drink, we also swallow air. When we take more air while drinking or eating, it comes out of the stomach through the mouth as a burp. Drinking sodas or other gassy drinks makes us burp more as these drinks contain extra gas. Sometimes, you may eat too fast, taking more amount of air inside and that too can make you burp.
So, how do you avoid a burp?
Burp is a natural human process just as how you pass motions and urine. However, due to good manners involved, it is always considered polite to burp quietly and to cover your mouth while burping. Also, avoiding spicy, oily food may help. Not to forget avoiding sodas. And mind you, over eating may also cause you to burp.
So always eat the right food at the right time at the right place in the right amount !