Outbound egress is traffic leaving a device, application, or network toward an external destination. In normal operations it can carry updates, telemetry, cloud sync, or user requests. In cyber security, the same path is important because it is where data can be exfiltrated and where malware can reach command-and-control infrastructure.
Defenders watch outbound egress to spot unusual destinations, unexpected ports, rare protocols, or devices that should not be talking outside the trust boundary. Controls such as egress filtering, DNS logging, proxy inspection, segmentation, and allowlists help limit what can leave the environment and make suspicious connections easier to detect. In sensitive systems, even a single unexplained outbound connection can justify an investigation.