What is a logarithm?

Logarithms, written in the form log_xy, are another type of mathematical 'operation', just like addition or multiplication. Subtraction as the opposite of addition, division is the opposite of multiplication and, likewise, logarithms are the opposite operation to exponentials, (e.g 3² = 9, log₃9 = 2).Take for example log₂8 = ?The answer to a logarithm is the exponential power the 'base' of the logarithm (in this case 2) must be given in order to be equal to the bigger number (here, 8). 2³ = 8, so therefore log₂8 = 3.