An opened nautilus shell. Its chambers make a logarithmic spiral

Logarithms or logs are a part of mathematics. They are related to exponential functions. A logarithm tells what exponent (or power) is needed to make a certain number, so logarithms are one of the inverse operations of exponentiation (the other one being roots). Historically, they were useful in multiplying or dividing large numbers.

An example of a logarithm is \displaystyle{ \log_2 8=3 }. In this logarithm, the base is 2, the power is 8 and the answer is 3. In this case, the exponentiation function would be: