Supply is said to be price inelastic if changes in price bring about changes in quantity supplied in less proportion. Thus, when price increases quantity supplied increases in less proportion, and when price falls quantity supplied falls in less proportion. The supply curve is steeply sloped and the elasticity of supply is less than one.
When price increases from P1 to P2, quantity supplied increases in less proportion from q1 to q2. This is the case when there are limited stocks of the product or the product takes a long time to produce such that when price rises, quantity supplied cannot be increased substantially.
Conversely, if price falls from P2 to P1, quantity supplied falls in less proportion from q2 to q1. This is the case of a commodity which is perishable and cannot be easily stored, e.g. fresh foods like bananas and tomatoes. These are perishable but not so highly perishable as fresh fish. When price falls, quantity supplied cannot be drastically reduced.