Resource Governor in SQL Server provides CPU, Memory and I/O throttling. In SQL Server 2014 and earlier, CPU throttling works only for similar kind of workloads and not for mixed workloads, where high importance workload group gets 9 slices of CPU, medium importance gets 3 slices and low 1 slice. In SQL Server 2016, CPU throttling works fine for all kinds of workloads.
The below video demonstrates this with hands-on example. SQLTest Tool simulates the hands-on labs for you, no registration necessary. You can practice the online hands-on example while watching the Video.