A session log is a recorded trace of what happened during a tool or terminal interaction. It may capture commands entered, outputs returned, timestamps, errors, and sometimes the files or resources touched during the session. In security work, session logs act as an audit trail that helps explain how a system was used and by whom.
Session logs matter because they let defenders reconstruct attacker activity, verify administrator actions, and spot suspicious behavior such as repeated login attempts, unusual commands, or scripted automation. They are also useful after an incident for containment and forensics. Attackers may try to avoid, delete, or alter logs to hide their tracks, while defenders preserve them in central logging systems or immutable storage so evidence is not lost. In tools that can run commands or access files, logs are especially important because they show exactly what the operator asked the tool to do.