

Normal (only depends on Date)
The interest rate changes on dates you specify. The interest rate is not influenced by the size of the amount of Principal.
Amount (depends on Date & Amount)
The interest rate changes on dates you specify, and also varies in accordance with the size of the amount of Principal.
Example: IF $0 - $10,000 is 5% and $10,001 - $20,000 is 6% THEN on $15,000, the whole amount is at 6%, Total $900.