The quantity of commodity a consumer is willing and able to buy at a particular time is called

The quantity of a commodity that a consumer is willing and able to buy at a particular time is called demand.
Demand refers to the consumer's desire or willingness to purchase a specific product or service at a given price and at a given time. It represents the customer's intent to buy and the amount they are willing to buy at various price levels.
It is important to note that demand is not just about the desire for a particular item, but also the consumer's ability to pay for it. For example, someone may wish or desire to buy a luxury car, but if they do not have the financial means to afford it, their demand for that car is limited.
In summary, demand is the quantity of a commodity that a consumer is both willing and able to buy at a given time, reflecting their desire for the product and their ability to pay for it.