What do exponential functions model in the real world? How does the standard equation form of the exponential equation change in each situation?

An exponential function is the function f (x) = ab^x, where a≠0, b>0 and b ≠1, and x is any real number. Important property of the exponential function is that it grows by common factors over equal intervals. In the real world exponential functions can model populations, electricity, temperatures, bank accounts, credit payments, compound interest, ...