How is an improper fraction defined in terms of the numerator and denominator?

An improper fraction is defined as a fraction where the numerator, which is the top number, is greater than the denominator, the bottom number. This characteristic is what distinguishes improper fractions from proper fractions, where the numerator is less than the denominator. When a fraction is improper, it typically represents a value that is greater than or equal to one, which can also be converted into a mixed number. Understanding this definition helps in identifying and working with different types of fractions in various mathematical contexts.