Demand which refers to the various quantities of a commodity or service that a consumer would purchase at a given time in a market at various hypothetical prices. In this it is always assumed that other things such as consumer’s income, his tastes and prices of related goods remain unchanged.

Ya D demand refers to the purchasing power .demand simply means quantity of any commodity that u can buy at certain price at a particular point of time

Demand for a commodity refers to:

The demand for a commodity refers to the quantity of the commodity that consumers are willing and able to buy at a specific price during a particular period of time. It represents the relationship between the price of the commodity and the quantity that consumers are willing to purchase.

Explanation:

1. Desire for the commodity:
- Desire for a commodity refers to the consumer's wish or inclination to possess or consume a particular good or service.
- While desire is a component of demand, it does not fully capture the concept. Demand also takes into account the consumer's ability and willingness to pay for the commodity.

2. Need for the commodity:
- Need for a commodity refers to the necessity or requirement for a specific good or service to fulfill basic human requirements.
- While need is a factor that influences demand, it is not the sole determinant. Demand considers not only basic needs but also wants and preferences of consumers.

3. Quantity demanded of that commodity:
- Quantity demanded refers to the specific quantity of a commodity that consumers are willing and able to purchase at a given price during a particular time period.
- It is influenced by various factors such as price, income, consumer preferences, availability of substitutes, and market conditions.

4. Quantity of the commodity demanded at a certain price during any particular period of time:
- This is the correct definition of demand for a commodity.
- Demand is not just about the willingness to buy a commodity but also the ability and intention to purchase it at a specific price during a specific time frame.
- It reflects the relationship between price and quantity demanded, showing how the quantity demanded changes with a change in price, holding other factors constant.

Conclusion:

In summary, the demand for a commodity refers to the quantity of the commodity that consumers are willing and able to buy at a specific price during a particular period of time. It encompasses not only the desire and need for the commodity but also considers the actual quantity demanded at different price levels. Understanding demand is crucial for businesses and policymakers to make informed decisions regarding production, pricing, and resource allocation.