Explanation/Reference: https://www.cisco.com/c/en/us/products/security/pxgrid.html

You can configure discovery rules to tailor the discovery of host and application data to your needs.
The Firepower System can use data from NetFlow exporters to generate connection and discovery events, and to add host and application data to the network map.
A network analysis policy governs how traffic is decoded and preprocessed so it can be further evaluated, especially for anomalous traffic that might signal an intrusion attempt

You can also monitor on-premises networks in your organizations using Cisco Stealthwatch Cloud. In order to do so, you need to deploy at least one Cisco Stealthwatch Cloud Sensor appliance (virtual or physical appliance).