In most human cultures, excessive flatulence is regarded as embarrassing and impolite.
The gases are most often produced by swallowing air, and frequently produced by certain types of food, mostly the fibrous type and the person's digestive system's reaction to them. The list includes beans, yams, sweet potatoes, chick peas, citrous rinds, chestnuts, broccoli, cabbage, etc. Lactating mothers are instructed to avoid gas producing food in their diet because breastfed babies can vomit when there is too much gas in their stomach.
Methane is the primary gas released; bovine flatulence is one of the primary sources of this [greenhouse gas]?. As methane is flammable, some flatulence is as well.
Colloquial and slang terms for flatulence include fart, cut the cheese, etc.