Extended Events are a lightweight monitoring system offered by SQL Server. Because the architecture uses so few system resources, they scale very well and allow you to monitor their instances, with minimal impact on user activity. They are also highly configurable, which gives you in your role as a DBA a wide range of options for capturing details from a very fine grain, such as page splits, to higher-level detail, such as CPU utilization. You can also correlate Extended Events with operating system data to provide a holistic picture when troubleshooting issues. The predecessor to Extended Events was SQL Trace, and its GUI, called Profiler. This is now deprecated for use with the Database Engine, and it is recommended that you only use it for tracing Analysis Service activity.