The Bihari inequality is a mathematical concept used in the field of analysis, particularly in the study of sequences and series. It provides a way to estimate the sum of a series by comparing it to a known function. This inequality is particularly useful in proving convergence properties of sequences. In its simplest form, the Bihari inequality states that if a function satisfies certain conditions, then the growth of the function can be bounded by a specific rate. This makes it a valuable tool for mathematicians working with differential equations and other areas where understanding growth rates is essential.