Meaning of “demand” - Learner’s Dictionary

demand

noun us uk /dɪˈmɑːnd/
There was an insatiable demand for pictures of the Princess.As people live longer, the demand for health care is projected to increase dramatically.The demand for mobile phones shows no signs of dropping off.Electronic services are rapidly expanding to meet demand.The demand for petrol increases the whole time.
NEED [ U, no plural ]

B2 a need for something to be sold or supplied:

There's an increasing demand for cheap housing.
REQUEST [ C ]

B1 a strong request:

They received a final demand for payment.
in demand

wanted or needed in large numbers:

Good teachers are always in demand.

(Definition of “demand noun” from the Cambridge Learner’s Dictionary © Cambridge University Press)