HP ArcSight Management Center 2.1 is a centralized management tool that simplifies security policy configuration, deployment, maintenance, and monitoring. It offers management and monitoring of ArcSight nodes, hosting of SmartConnectors, and benefits such as rapid implementation of security policies, reduced errors, and lower expenses. New features in 2.1 include improved user management, logger management enhancements, connector and configuration management features, improved monitoring, and node management enhancements. The document provides technical requirements and instructions for upgrading ArcSight Management Center software.