Log

A log can be:

a cut portion of a tree bole or large branch (see logging)
a time-sequential data record (see data logging)
a logarithm used in mathematical calculations
a log (speed) to measure the speed of a ship
a Ship's log of important events in the management, operation and navigation of a ship
a function present in many programming languages that calculates the natural logarithm of a number (see log (programming))
the Wikipedia logs, at Special:Log
a fictional toy advertised on the Ren and Stimpy cartoon.