Bro,
Have you checked out "How Stuff Works" ? There is a specific write up that gives great pictures and stuff.
That said, Laymans terms, adjusting cam timing is equal to adjusting the rate at which you breath in and out.
If your body is at rest, the breathing rate (Cam Timing) will be very much different from when you are running after Ben Johnson in the 100m sprint.
Hence get the two mixed up, like running after Ben Johnson with a breathing rate set to rest.... well... you get the picture now.