Session visibility is the ability to observe what an authenticated browser session is doing in real time. It goes beyond knowing that a user logged in: defenders can see page activity, consent prompts, privilege changes, data access, and suspicious navigation while the session is active.
This matters because many attacks abuse valid sessions instead of breaking in again. A stolen cookie, a malicious browser page, or a phishing flow can let an attacker operate inside normal web apps while looking like the user. With session visibility, security teams can spot abnormal behavior such as unusual file downloads, risky OAuth consent, access from an unexpected location, or rapid movement across services. On the defensive side, it supports alerting, investigation, and fast session revocation before abuse turns into data loss.