What are the token standards in Sui, and is it possible to create ERC-20 tokens on the Sui blockchain?
There is the basic coin here. SUI is such a coin. You can create them by using coin::create_currency as SUI does here.
If you want a little bit more regulation you can have a deny-list with coin::create_regulated_currency. This will also produce a DenyCap for your Coin in order to be able to ban addresses from using it.
If you want more advanced schemes such as a whitelist or something with more logic you can use sui::token. This uses actions and rules stored inside its TokenPolicy in order to be able to program more complex circulation limitation use-cases.