The clock is like the rhythm to a song: each word is sung to each beat; the faster the beat, the faster we can complete the song. Generally, the processor obeys (called “executes”) each command in a certain number of clock beats (called “clock ticks”). The faster the clock the faster things get done.

“Wait a minute, why is the next family member faster than the first at the same clock rate?” you might hear (e.g. the Pentium/66 is twice as fast as a 486/66). It is the aim of each processor generation to do things faster and better than the generation before. The
80286 processor required about 50 clock ticks to complete a multiplication. The next generation (80386) only took 10 clock ticks! Again, the more you can do within a clock tick and the faster the clock, more can be done in less time.

You may think that naming processors with numbers might be rather sterile and boring. Well, they are. In fact, until recently processors and chips were given numbers for names (e.g. Z80, 6502, 68000, etc.). Now we have the Pentium and the Pentium Pro (this last one was “quite original”). Most of the time, the numbers follow a sequence: the bigger the number within a family, the faster/better/more complex it is. Then as time passed individual processors could go varying speeds (the 80386 entered the market running a dazzling 16MHz; about six months later Intel introduced the 20 and 25MHz versions, 25% and 56% faster, respectively).