Network telemetry is the collection of logs, flow records, packets, and connection metadata that describe how devices communicate across a network. It can include source and destination addresses, ports, DNS lookups, session timing, bytes transferred, and protocol details. Unlike a single browser record or endpoint event, telemetry shows observed behavior on the wire, which makes it useful for validating what a system actually did.
In cyber security, network telemetry matters because it helps confirm or dispute other evidence. Investigators can correlate browser history, cache, downloads, and host logs with network signals to rebuild a timeline. Defenders use the same data for intrusion detection, threat hunting, and spotting exfiltration, command-and-control traffic, or suspicious lateral movement. Good telemetry often turns a vague clue into a testable pattern.