Egress pricing is the charge a cloud provider applies when data leaves its network or crosses certain cloud boundaries, such as regions, zones, or other services. Unlike compute or storage, egress is tied to data movement, so the bill can grow quickly when applications replicate backups, stream logs, serve downloads, or transfer large training datasets between environments.
In cyber security, egress pricing matters because defenders often need to move evidence, telemetry, or backups out of a cloud environment during investigations, recovery, or multi-cloud operations. Attackers can also create costly outbound traffic by exfiltrating large volumes of data or triggering abuse of public endpoints. For this reason, security teams watch egress patterns closely and design controls such as network segmentation, data residency planning, and cost alerts to reduce both risk and surprise charges.