What is the traditional skirt worn by ballerinas called?

This isn’t a science question. It’s a culture question

I’m a Math teacher. Your equation problems have wrong answers!!! Check “Order of Operations” rules.

first ballet I ever seen was the Nutcracker. I really enjoyed it.

My mum was a professional ballet dancer, unfortunately she stopped before I was born so never got to see her do swan lake etc, but she encouraged my sisters & myself to do so but we never got into it like she did