When the numerator of a fraction is less than the denominator, we call it a true fraction. When the numerator of a fraction is higher than the denominator, we call it a false fraction.
Note: to judge whether a formula is a fraction or not, the key is to meet the following requirements: the denominator of a fraction must contain letters and the denominator of a molecule is an algebraic expression. There is no need to consider whether the score is meaningful, that is, whether the denominator is zero.