Completely Fair Scheduler
The Completely Fair Scheduler (CFS) was a process scheduler that was merged into the 2.6.23 (October 2007) release of the Linux kernel. It was the default scheduler of the tasks of the SCHED_NORMAL class (i.e., tasks that have no real-time execution constraints) and handled CPU resource allocation for executing processes, aiming to maximize overall CPU utilization while also maximizing interactive performance.
Source: Wikipedia — Completely Fair Scheduler (CC BY-SA 4.0)