What is the bottom number of a fraction referred to as?

The bottom number of a fraction is referred to as the denominator. The denominator indicates how many equal parts the whole is divided into. In a fraction, the numerator (the top number) represents how many of those parts are being considered. For instance, in the fraction 3/4, the 4 is the denominator, meaning the whole is divided into 4 equal parts, and 3 of those parts are being counted. This understanding is crucial in various mathematical concepts, such as comparing fractions, performing operations with fractions, and understanding ratios.