Cisco Firepower Threat Defense (FTD): This is the core security software that provides firewall, intrusion prevention, malware protection, and URL filtering capabilities.
Cisco Firepower Management Center (FMC): This software is used to centrally manage and configure FTD instances. It provides a unified management interface for firewalls, application control, intrusion prevention, URL filtering, and advanced malware protection.
The Cisco 4100 series appliance is designed to run these two software components together to provide a comprehensive security solution.