Most network-able equipment has the ability to record, based on predetermined settings, events or a history of activity. These events, called system logs, can be as simple as a port on a switch getting disconnected or as specific as a table on a database running out of room. The information contained in the events can be easy to read or very cryptic and each manufacturer seems to follow a different standard. Some equipment system logs can be a great source of information and others are completely useless. SANS Institute teaches a very valuable concept, .Know Thy Network.”]
Source: https://www.cuinfosecurity.com/reviewing-equipment-system-logs-do-i-have-to-a-314