First, there is the "200 Kronor Note". This is used to pay for everything you might buy in a small local shop or cafe, admission to a museum - or several can be combined to buy rail tickets or items that are marginally too big to fit in your pocket. (Restaurants and larger items require credit cards).
The other denomination is "change from a 200 Kronor note". This consists of a series of basically worthless notes and coins.
I am told if you stay for more than 2 weeks you may save up enough "change from a 200 Kronor note" to exchange it at a bank or post office for " a 200 Kronor Note"