Thanks for the info UBrales as i did'nt know this either
In the book "Upgrading & Repairing PCs" by Scott Mueller, he illustrates this point very well using the example for a diner at a restaurant. I have it in a PDF format which will not permit me to copy and paste.
Illustration of cache (by Scott Mueller):
L1 cache is built into the processor die and runs at full processor speed, which is FSB x multiplier. As a result, L1 cache is much faster than the motherboard speed. Using cache reduces the time that the CPU has to wait for data from the main memory (RAM) which is much slower when compared to the CPU speed.
Chapter 3, page 65 to 68 in the book (size of an encyclopedia).