Differences between processors can be confusing.
When you buy a car, you want to compare features and the same holds true when you buy a computer. Comparing Celeron to Pentium 4 is like comparing a 4 cylinder to a 6 cylinder engine .
Celeron
According to Build Gaming Computers, Celeron processors are the low-end processor intended for standard home computer use. SciNet reports the best Celeron processor has an L2 Cache of 128kb, a clock speed limit of about 2.0 GHz and runs at a core voltage of 1.75V. These are useful numbers for comparison.
Pentium
The top Pentium processor is the Pentium 4 Prescott. CPU Scorecard reports it has an L2 cache of 1MB (1024kb), a potential 3.0 GHz clock speed and runs at about 1.4V. The lowest performing Pentium 4 processor, the Willamette, has an L2 cache of 256kb, a potential 2.0 GHz clock speed and runs at about 1.7V.
What the Numbers Mean
PC TechGuide explains the L2 cache reduces information transfer delay so the larger cache is more desirable. Clock speed helps determine processing speed so higher numbers are again desired. Voltage refers to the power needs of the processor. This contributes to the heat generated and battery life if used in a laptop, so lower numbers are better.
Tags: Celeron Pentium, clock speed, clock speed runs, Pentium processor, potential clock, potential clock speed