L2 Cache & Front Side Bus

Thinking about upgrading to a new Dell for Digital Audio work (PC based multitrack recording, sampling & sequencing.) The machine I looked at sports a 2GB P4 CPU, with I believe a 512KB L2 Cache; & a 533MHz Front Side Bus on the motherboard. My questions are:
1) What is the Level 2 Cache (how does it work; & how is it different from memory)?

2) Is the Front Side Bus the same animal as the PCI Bus?

As a general inquiry, will these two items be more beneficial in recording audio to the PC?

Thanks in advance.

mark4man