What is a relatively horizontal (but not completely flat) demand curve?

A relatively horizontal demand curve indicates that consumers are highly responsive to price changes, meaning that small decreases in price can lead to significant increases in quantity demanded. This elasticity suggests that the product has many substitutes or that it is a non-essential good, where price fluctuations greatly influence consumer behavior. While not completely flat, a relatively horizontal curve shows that demand can vary widely with price changes, highlighting the sensitivity of consumers to price variations.