Nushera, castor sugar is a British term. Starting on page 432 of the Cake Bible, Rose has a very informative section on the various types of sugar. Happy new year.
Hi Rozanne- Happy New Year. Here in Aus we have regular white sugar, raw sugar, light and dark brown sugar, icing sugar(powdered sugar with or w/o cornstarch), and caster(look how it spells) sugar. regular white sugar is pretty “fine”, caster sugar even finer. btw, i have used/tasted “regular” sugar produced in US, EU, Indian subcontinent and Aus and found the Aussie sugar to be the sweetest. “foreign” recipes often become “horribly sweet” if sugar is not reduced.