Reference:
Flow-based inspection is a type of traffic inspection that is used by some firewall devices, including FortiGate, to analyze network traffic. It is designed to be more efficient and less resource-intensive than proxy-based inspection, and it offers several benefits over this approach.
Two benefits of flow-based inspection compared to proxy-based inspection are:
FortiGate uses fewer resources: Flow-based inspection uses fewer resources than proxy-based inspection, which can help to improve the performance of the firewall device and reduce the impact on overall system performance.
FortiGate adds less latency to traffic: Flow-based inspection adds less latency to traffic than proxy-based inspection, which can be important for real-time applications or other types of traffic that require low latency.