A kadia is an Indian wok.
The kadai is normally used for deep-frying, stir-frying, and making curries. It is a round bottomed heavy cookware with two loop shaped handles extending from the rim. Larger versions are called 'Kadha'. Nowadays, a smaller version of the same in brass or copper is used to serve rice based or gravy based dishes in restaurants serving Indian cuisine.
The traditional Kadai is usually made of thick high-carbon iron, cast-iron, brass, or aluminium. Better quality kadais have a heavy bottom where a layer of aluminium is sandwiched between two layers of stainless steel for better and even heat distribution. Nowadays they are also available in the non -stick (Teflon coated) material, hard anodised aluminium too. Some of them are available with lids too.