Kadai is neither a wok nor an Indian set pan. It has large, curved handles that have space between them so it looks like mini tawa placed upside down within the make up of kadai/iron kadai/non stick or stainless steel Kadii.
The major difference from this gadget and its non-stick version (Kadhia) is that in non stick model you need to add oil for cooking but in kadai all you need is to add water. An important feature of kada, as explained earlier is that heat doesn't have to build up at the bottom and when covered with lid it also helps in preserving food for a longer time upto two hours rather than opening the lid for short duration which further provokes more pressure over frying pan resulting into momentary burning out of food from moisture inside.