The expression "m*n" represents the multiplication of two variables, m and n. In mathematics, multiplication is a fundamental operation that combines groups of equal size. For example, if m equals 3 and n equals 4, then "m*n" equals 12, which can be visualized as 3 groups of 4. In algebra, "m*n" can also represent the area of a rectangle where m is the length and n is the width. This concept is essential in various fields, including geometry, physics, and engineering, as it helps in calculating dimensions and quantities in real-world applications.