CPU Usage going up and down. Why?

[salm2s]

Hi,
Why do CPUs usage always go up and down.
For E.G: It will be at 17%, then it will be 4%, then it will suddenly be at 26%

Thanks,
salm2s

 

[dulelele]

Well it is cpu usage after all, it just happens to be that at some point is jumpd bc it is used more, for example when playing a shooting game, your cpu usage might jump up when you shoot be ause the cpu is calculating where the bullet will go.