Splunk Enterprise Security is an advanced security information and event management (SIEM) and security intelligence platform that allows organizations to monitor, detect, investigate, and respond to cyberattacks and threats. It provides risk-based analytics, security intelligence, continuous monitoring of security domains, and incident response capabilities through features like alerts and dashboards, pre-built searches, threat intelligence integration, and an investigation timeline. The platform helps connect data from various sources to gain security insights and identify unknown threats.