Quick one today

Sql Server has its own operating system that manages several things before the commands are sent to Windows Operating System. All Sql Server services a.k.a. SSRS, DB Engine rely on SQLOS for

1. Memory Management
2. Scheduling
3. Synchronization
4. Memory Brokers
5. Exceptional Handling
6. Deadlock Detection
7. Extended Events
8. Asynchronous I/O

While it performs all the above and more tasks, Memory Management and Scheduling are some of its primary tasks.

Hope this helps,
_Sqltimes