On the CPU tab of the Resource Monitor of Windows 10 64 bit, it shows the "CPU - Total" graph and 1 graph for each CPU, but then it also shows a graph for "Service CPU Usage".
What is "Service CPU Usage"?
It is the same in Windows 8.1
The subtotal of CPU usage for all the svchost.exe's or services that are part of Windows Services. Each generation of Windows has compartmentalized tasks to restrict permissions to "NetworK" "System" "Dcom" etc which are like functions within Windows with group restrictions to improve security.
As a result. the number of Windows services have increased at least 50% or so each generation from XP to X so there are several hundred services grouped by Process host "svchost"
My services do not have Windows Search enabled which with Windows Update can make your PC sluggish if limited in power and RAM.
The only security I need is a dog who barks at the door.(Molly) same as on my PC (Scotty from Winpatrol) All other features like Windows Defender have been disabled for years. I've have been following this practice for about 10 yrs with good results. ( your mileage may vary)