Topic summary
CPU usage

Extracted from the Wikipedia article CPU time.
CPU time (or process time) is the amount of time that a central processing unit (CPU) was used for processing a specific set of instructions of a computer program or operating system, as opposed to total time from start to finish, where the CPU might have spent time on other processes. See the figure. CPU time is measured in clock ticks or seconds. Sometimes it is useful to convert CPU time into a percentage of the CPU capacity, giving the CPU usage.