BCNA is the native coin on the BitCanna chain. In order to work with very small amounts (for example when calculating transaction fees), ubcna is used.
1 BCNA equals 1000000ubcna, as "u" stands for micro. Example: 10,11 BCNA equals 10110000ubcna.
BCNA and ubcna are also called the denom of the BitCanna native coin.