What is demand?
Demand is the quantity of your product a customer wants. If your product is cheaper than your competitors then usually your product will have a higher demand. Also if a new product is released then it will have a higher demand than a product that has been out for longer. For an example if a new game is released tomorrow it will have a higher demand than the previous game.
If your product is branded that will also have a higher demand and people will pay more for better quality. This can trigger repetative purchase. This means your customer is happy enough with your product they will actually rely on it for their weekley shop.