Log

A log is a record of the activity of a computer system, often stored in a particular file.

Description
Different operating systems have different conventions and support for storing logs. Unix has the system and the   directory hierarchy, Microsoft Windows uses s. Web servers, for example, typically record information about every page accessed in one or more "web logs".

Usage by Apple
Classic Mac OS up through Mac OS 9.x did not have a standardized method of storing log information, which was left up to individual installer and updater utilities to save log files where they saw fit.

macOS (formerly Mac OS X and derived from NeXTSTEP) uses a method similar to Unix and stores its logging information in the   directory, which is hidden from the user by default. There is also a   directory in the Library folder, which is accessible to the user. In November 2022, a Mac OS X 10.2.2 (Jaguar) update added journaling, a form of logging of disk activity, to the HFS Plus drive format to reduce the likelihood of data corruption following an unexpected power outage, restart, or disconnection. In April 2005, Mac OS X 10.4 (Tiger) introduced Apple System Logger (ASL), replacing the original syslogd daemon. Starting with macOS 10.12 (Sierra) and iOS 10 in 2016, Apple switched from Unix-style logs to macOS Unified Logs stored in  files. Records of log files can be accessed through the Console utility.