Wilhelm Ackermann was a German mathematician known for his contributions to mathematical logic and the foundations of mathematics. He is best recognized for the Ackermann function, which is a classic example of a computable function that is not primitive recursive. This function illustrates the differences between various classes of functions in mathematical theory. Born in 1896, Ackermann's work laid important groundwork for later developments in computer science and logic. He also contributed to the study of set theory and model theory, influencing how mathematicians understand the structure and behavior of mathematical systems. His research remains relevant in various fields today.