Various Types of CPUs :

Intel CPUs :

1982 — Intel 80286

1985 — Intel 80386

1989 - Intel 80486 / 80486DX2 - 1992

            Intel Pentium-I  (P-I) 
            Pentium-II
            Pentium-III 
            Intel Pentium-IV
            Intel P4 Dual Core  - 2 core
            Intel Pentium Core 2 Duo - 2
        

Major change was made with the Intel Core i Series