What is Log ?
Log is (noun) 1. a thick piece of a tree He brought in a load of logs for the fire. to sleep like a log to sleep very deeply After his 12-mile walk he slept like a log. 2. a record of details such as speed or position especially on a ship or plane The ship’s log gave details of their position when the fire broke out. (verb) to write down details of something which has happened in a book as a record Have you logged your day’s activities into the book?
source: Easier English, Student Dictionary Upper Intermediate Level