An improper fraction is a type of fraction where the numerator, or the top number, is greater than or equal to the denominator, or the bottom number. For example, in the fraction 7/4, the numerator 7 is larger than the denominator 4. Improper fractions can represent values greater than or equal to 1. Improper fractions can be converted into mixed numbers, which consist of a whole number and a proper fraction. For instance, the improper fraction 9/5 can be expressed as the mixed number 1 4/5. Understanding improper fractions is essential for working with fractions in mathematics.