As Intel developed different generations of CPUs, it created a numbering system to identify each generation.

Intel's first generation was the 8088, the second 80286, the third 80386, the forth 80486. Do you see a pattern here? Starting with the second generation, the third digit of the chip number indicated the generation.

How do you think the fifth generation was numbered? If you suggested 80586, it was a good guess. But the correct answer is Pentium. Why? Intel's CPU numbering system was becoming generic, and the courts would not let them have a trademark on numbers. So Intel decided to pick a name for their next CPU: Pentium.