Bus speed vs. front side bus

[Steveplanetary]

My CPU is an Athlon-XP-M (laptop) 2400+ running at ~1.8 GHz under full load (multiplier 13.5) down to 530 MHz (multiplier 4.0). These speeds are obviously related to what CPU-Z calls Bus Speed (133 MHz). CPU-Z also reports a Rated FSB of 265 MHz. My questions are: 1) What is the difference between Bus Speed and Rated FSB? and, 2) What components are running at which speed?

I appreciate any insight you can provide. Thanks

Steve