The gas cylinders are used for cooking either with gas stoves like I have (4 gas burners plus an oven with a broiler) or with what those from the US and Canada would think of as camping stoves with one to three burners, although they don’t come with the wind shields like the camping stoves do.
Most people can’t afford stoves with ovens, so either use the camping stoves with the gas tanks or use other forms of fuel for cooking, like kerosene cookers, wood, coconut husks, and so on. And, even when they have a stove with an oven, the oven is seldom, if ever, used.
Personally, I use our oven frequently. I have a feeling, though, that Fahim’s mother has never used hers.