Data flow monitoring is the tracking of how information moves between users, devices, applications, and external services. It can use network telemetry, endpoint and cloud logs, identity records, or data-loss prevention tools to show where data is sent and which systems handle it.
In cybersecurity, this visibility helps organizations detect unauthorized transfers, investigate suspicious activity, and enforce rules for sensitive information. For example, monitoring may reveal employees sending corporate data to an unapproved AI service. It does not automatically prevent that transfer, so defenders often combine monitoring with access controls, approved-service inventories, alerts, and policies that define how data may be shared.