Ot to be confused with economic stickiness, elasticity is an
underlying theory in matters of pricing and demand that deals with
response. The elasticity of good refers to how quickly then said good
responds to a specific factor. In this light the common concept
"price elasticity of demand" deals with the responsiveness of
demand to a change in price. When a product is said to be price elastic,
it means that the demand for the product changes according to the
specific price. Although this seems natural in accordance to the law of
demand, computing the actual price elasticity assists firms to boosts
their revenue by tweaking prices by just the right amount. Some
commodities such as cigarettes, alcohol or even oil have a unique
situation. Despite changes in price the demand for these commodities
remains virtually the same. Such goods are said to be price inelastic.
Source: G.F Stanlake. Introductory Economics.