Authentication records are logs that show when a user, service, or device tried to prove its identity. They can include successful and failed logins, session creation, token use, MFA prompts, IP addresses, timestamps, and device details. In security work, these records are one of the first places analysts look when they need to determine whether an account was used by its real owner or by an attacker.
They matter because many intrusions begin with stolen credentials, phishing, token theft, or abuse of valid sessions. Authentication records can reveal unusual geographies, impossible travel, repeated failures, new devices, or access at odd times. Defenders use them to confirm a claim, trace lateral movement, support incident response, and decide whether an alert reflects real compromise or normal activity. Strong logging and retention make these records much more useful for both detection and investigation.