Basis is a multiplier used to calculate the total interest paid or received in a defined time period. It is typically used in accounting and valuation for bonds, swaps, dividends, project finance, and other investments with periodic cash flows. Basis is also known as the "day count convention" because it defines how days in a year are treated for calculation purposes in different parts of the world.

Price
Used for Commodity based assets. The interest periods for a Commodity swap are always from the first of the month to the end of the month inclusively. Payment is calculated as price x notional.