Sure you are confused about the Iranian rial and toman. You are surely thinking that those are two different words with different meaning. These are the Iranian words that are used for their currency. So, there is no difference between rial and toman. Official currency in Iran is rial. The word toman is used by the local people, especially in the daily based payments and for sure, sometimes it is confusing for the ones that are not Iranians. The common bill these days is 10 000 rial bill, but the local people use tomans, which is deducting one zero. A 10 000 rial bill is called 1000 tomans bill. So, 10 000 rial is equal to 1000 toman and that is approximately $1 . We have to say that official dollar exchange rate is somewhere between 1030 and 1040, which fluctuates a bit up or down. The fluctuations are bigger in the free market. The common types of rial bills are 500, 1000, 2000, 5000, that are available both in coins and bills, and just available in the bills there are 10 000, 20 000, 50 000, 100 000. When the tourist are coming and the passing by travelers are exchanging they usually change the most in 50 000 bills. Before there were available the 100 and 250 bills and coins. Today, you can sometimes, still find here and there these 100 and 250 bills or coins. They were used to function as dime and quarters. For example, we will make you a clear image. For example, one hamburger costs 2000 tomans, which is equal to 20 000 rials and that is equal to $2. A mineral water bottle cost 500 toman = 5000 rials = 50 cents. And the exchange rate market is making quite easy and simple to pay for food or any other service when you are a tourist or a traveler in Iran. But one thing you have to remember. Never mix up the rials and toman. They are same but not same at some point. In back and official working places the official currency is rial and that is only acceptable currency there. In the everyday life, and in free market the toman can be used properly.
Finally, we come to cheque Rial which came as a result of the sanctions imposed by USA against Iran back in Trump Era. These are inflation cheque money and there are two cheque Rial denominations: the 500K Bill and the one Million Bill ( which is the largest denomination of Iranian currency. These two bills came to cover the market need for a large bill increase purchasing power.