The law of demand says that QD and price are
Inversely related
What I not held constant when moving along a stable
Price
Income effect
Increase or decrease in purchasing power brought on by change in price
Diminishing marginal utility
Utility or satisfaction decreases as more of the same product is consumed
Demand
The quantity consumers are willing and able to buy at various prices during a given time period
Elastic
Expensive , luxury, substitutes, has durability,
Asks a long time
Inelastic
No substitute, necessity, lasts short time, no durability, cheap