Introduction to Logarithms

Q1: What is a logarithm?
A1: A logarithm is a convenient way of expressing an exponential function.
Given: $y=b^x$
Equivalent: $\log_b(y)=x$

Q2: What's a common logarithm?
A2: A common logarithm is a logarithm that uses base 10.
It's written as: $\log(y)=x$

Q3: What's a natural logarithm?
A3: A natural logarithm is a logarithm that uses base $e$.
It's written as: $\ln(y)=x$