The Firepower System uses network discovery and identity policies to collect host, application, and user data for traffic on your network. You can use certain types of discovery and identity data to build a comprehensive map of your network assets, perform forensic analysis, behavioral profiling, access control, and mitigate and respond to the vulnerabilities and exploits to which your organization is susceptible.
You can configure your network discovery policy to perform host and application detection.
Reference: https://www.cisco.com/c/en/us/td/docs/security/firepower/640/configuration/guide/fpmc- configguide-v64/introduction_to_network_discovery_and_identity.html