Kitty refers to the amount collected at the party, every member contributing a certain sum of money each month. The kitty is handed over to one member of the group every month. The chit funds operate along similar principles.
It is usually held at a specified time each month, by a specific group of women. Every member of the group has to host a party at least once. The hosting member organises food and other logistics, and the party is usually a gossiping place for women. In most of India, it is usually simply referred to as a 'committee'.
The party may include games, and may involve a theme with related costumes and foods.