New Relic and Splunk are two prominent tools in the world of observability and monitoring, each serving distinct purposes. New Relic is used for Application Performance Monitoring (APM), offering a full-stack observability platform. It is important to note that New Relic is not a SIEM tool, its primary focus is performance monitoring. On the other hand, Splunk is used for log management, machine data analytics, and is widely utilized as a SIEM tool.