What set of numbers are fractions?

Fractions are numbers that represent a part of a whole and are expressed as the ratio of two integers, where the numerator (the top number) indicates how many parts are being considered, and the denominator (the bottom number) indicates the total number of equal parts in the whole. For example, in the fraction 3/4, 3 is the numerator and 4 is the denominator. Fractions can be proper (numerator is less than the denominator), improper (numerator is greater than or equal to the denominator), or mixed numbers (a whole number combined with a proper fraction).