The logarithm is the inverse function to exponentiation that will given number x is the exponent to which another fixed number, the base b, must be raised, to produce that number x. Logging is the act of keeping a log. In the simplest case, messages are written to a single log file. In computing, a log file is a file that records either events that occur in an operating system or other software runs, or messages between different users of a communication software.