The expression "x < y" is a mathematical inequality that indicates that the value of x is less than the value of y. This means that if you were to compare the two values, x would be positioned to the left of y on a number line. For example, if x is 3 and y is 5, then 3 is indeed less than 5. Inequalities like "x < y" are commonly used in various fields, including mathematics, science, and economics. They help in understanding relationships between quantities, making predictions, and solving problems. Recognizing these relationships is essential for analyzing data and making informed decisions.