Demand may be described as "very good," "good," "moderate," "light," or "very light" in relation to what is considered typical or normal demand at each market or marketing area for the day or period, allowing for seasonal changes.  In evaluating demand, the reporter will bear in mind that a good demand might exist for certain grades, weights, or classes, while at the same time, others are in light demand.  A reporter should be currently informed as to the nature of demand as indicated by the estimated proportions sold to local packers, order buyers, feeder dealers, etc.  Indicated shifts in the needs of the various buying interests could well be a forewarning of a changing market.  Demand should not be confused with "market activity."  An active trade at firm to higher prices for light supplies does not necessarily imply a better demand than existed the previous day for larger supplies.  Neither does a slow trade at weak-to-lower prices on heavy supplies mean a light demand, since the price level may be influenced by expansion of the supply rather than by contraction of demand.