Processors:

Also known as the CPU (Central Processing Unit).  The CPU is a major part of your computer. The CPU is what determines how fast your system operates.  It is the "Engine" of your system.  

Intel processors are available as Celeron (slower but inexpensive),
Pentium II & Pentium III (mid-range), & Pentium 4 (best for performance).  

AMD processors are available as Duron (slower but inexpensive),
Athlon (mid-range), & T-Bird (best for performance).