Definition - What does NetFlow mean?
NetFlow is a networking protocol designed by Cisco Systems for logging and recording the flow of traffic received and sent within a network.
NetFlow was designed in collaboration with Enterasys Switches. It provides network traffic statistics by collecting related data from enabled routers and switches. NetFlow may also be called Cisco IOS NetFlow.
Techopedia explains NetFlow
NetFlow is primarily designed for network administrators and managers to help them with detailed information, statistics and overall network operation data. NetFlow is integrated within the proprietary Cisco IOS installed on the supporting routers and switches by default and works by registering all of the IP traffic that flows in and out of the network through these devices.
The information recorded by NetFlow is used for a variety of network management and maintenance tasks such as traffic logging, usage statistics monitoring, and anomaly detection, which it accomplishes through network capacity planning and monitoring, and by monitoring unusual traffic trends .