Negative integers are whole numbers that are less than zero. They are represented on the number line to the left of zero and include numbers like -1, -2, -3, and so on. Negative integers are used in various mathematical contexts, such as representing debts or temperatures below freezing. In mathematics, negative integers are important for understanding concepts like subtraction and absolute value. When you subtract a larger number from a smaller one, the result is a negative integer. They also play a role in real-world situations, such as measuring elevation below sea level or calculating losses in finance.