It seems that what you're describing is the futures curve, which is either a normal curve (longer maturity is larger than front month), or inverted, longer maturity is less than front month. Contango vs. (Normal) Backwardation describes the shape of prices within a given contract's window of trading up until expiry, i.e. the contract must converge on the spot price as expiry nears. These two are often confused it seems, even in professionally written prospectuses. This is explained in more detail here: http://www.investopedia.com/articles/07/contango_backwardation.asp?viewed=1