Final answer:
A demand curve is typically a downward-sloping line, reflecting the law of demand where higher prices lead to lower quantity demanded and vice versa. While there can be exceptions, the standard representation indicates an inverse relationship between price and quantity demanded.
Step-by-step explanation:
A demand curve can most accurately be described as a downward-sloping curve or line in most cases. This visual representation stems from the basic principle known as the law of demand, which explains that as the price of an item increases, the quantity demanded of that item tends to decrease, and as the price decreases, the quantity demanded tends to increase. This relationship generally results in a demand curve that slopes down from left to right, reflecting the inverse relationship between price and quantity demanded.
While demand curves can potentially be represented by other shapes or slopes, such as a horizontal line reflecting perfect elasticity, these are more exceptional cases. The standard representation of a demand curve as it is commonly taught in economics is a downward-sloping line, reflecting the typical consumer behavior in response to changing prices.