There are many different slots and sockets for CPUs, the slots correspond with processor types and with processor manufacturers. Newer sockets, those with a three digit number, are named after the number of pins they contain, where as older ones are named in the order of their invention or generation and usually contain a single digit.

Sockets supporting Intel CPUs

• Socket 1 - 80486SX, 80486DX, 80486DX2, 80486DX4
• Socket 2 - 80486SX, 80486DX, 80486DX2, 80486DX4
• Socket 3 - 80486SX, 80486DX, 80486DX2, 80486DX4
• Socket 4 and 5 - early Intel Pentium processors
• Socket 6 - 80486DX4
li>Socket 7 - Intel Pentium and Pentium MMX
• Socket 8 - Intel Pentium Pro
• Slot 1 - Intel Pentium II, older Pentium III, and Celeron processors (233 MHz - 1.13 GHz)
• Slot 2 - Intel Xeon processors based on Pentium II/III cores
• Socket 370 - newer Pentium III and Celeron processors (800 MHz - 1.4 GHz)
• Socket 423 - Pentium 4 and Celeron processors (based on the Willamette core)
• Socket 478 - Intel Pentium 4 and Celeron processors
• Socket 603/604 - Intel Xeon processors
• Socket 755 - Intel Pentium 4 and Celeron processors

Sockets supporting AMD CPUs

Socket 7 - AMD 80486, K5, and K6 processors

SuperSocket7 - AMD K6, K6-2, and K6-3 processors

Slot A - older AMD Athlon and Duron processors

Socket 462 (or Socket A) - newer AMD Athlon, Athlon XP, and Duron processors

Socket 754 - lower end AMD Athlon 64 with single-channel memory support

Socket 939 - AMD Athlon 64 and AMD Athlon FX with dual-channel memory support

Socket 940 - AMD Opteron and early AMD Athlon FX processors