No matter how much ever I explain or write about IBM Tivoli Endpoint Manager's (a.k.a BigFix) architecture, its best to understand the architecture and working via this 4 minute animated video.
Top competitive differentiators of TEM:One for all solution - One product to manage all endpoints (physical,virtual,client class,server class)
Technically speaking 1 console, 1 agent, 1 server: 250,000 endpoints, 90+ OS versions
Ease of use - Intuitive console, wizards for common tasks and a very simple scripting language.
Automatic product update - of features and content through the TEM content delivery cloud based service and exploits the subscription based model (Get what you subscribe for).
Pull model - Real-time endpoint configuration evaluation and enforcement in contrast to relying on a central server to push queries and gather configuration settings.
Scalability - True Enterprise scalability with minimal infrastructure.