The Socket 7 connector was introduced by Intel with the Pentium 133 processor, and replaced the Socket 5. The Intel Pentium and Pentium w/MMX, the AMD K5 and K6 (all variations), the Cyrix 6x86 and MII, the IDT Winchip and Winchip-2 and the Rise mP6 are all Socket 7 processors. The processor is encased in a flat ceramic or plastic package with pins extending down for insertion into the socket. The socket has a lever that, when up, aligns the holes of two sliding surfaces to allow the processor to drop in. When the lever is again lowered, these surfaces slightly misalign, securing the processor pins in place and providing an electrical connection. This design is called the ZIF socket (Zero Insertion Force).

With the introduction of the Pentium II, Intel changed the way the processor is mounted. Intel wished to move the Level 2 cache from the motherboard closer to the processor in order to speed up the data transfer. They had done that with the Pentium Pro by packaging it in the ceramic with the processor chip (called Socket 8). This turned out to be too expensive due to the number of pins required and the cost of the on-package SRAM. To lower the cost of the Pentium II, Intel mounted the processor chip and commodity SRAM chips onto a cartridge. This cartridge (Single Edge Cartridge, or SEC) is inserted edgewise into a slot on the motherboard (called Slot 1). This type of package was also used for the Celeron processors until this year.

Just like the Socket 8 connector, Slot 1 is proprietary, which has prevented rival processor and chipset manufacturers from offering competing products. This has resulted in higher prices for Slot 1 based products, however Intel recently licensed other manufacturers, including VIA, SiS and ALi to make chipsets. Even more recently, Intel has filed suit against VIA to revoke that license, but VIA may have side-stepped the issue by purchasing Cyrix and entering into a manufacturing agreement with TSMC, who apparently has rights to produce processors and chipsets

The newest connector as of this writing is the Socket 370, which is also an Intel proprietary design. This is currently used only for Celeron processors, but future Pentium III processors will also use this package. Due to the shrinkage of the processor circuitry, Intel can now include the L2 cache on the chip for no additional cost over the chip itself. As a result, they have gone back to a package similar to the old Socket 7 package (though it has more pins, and thus is not compatible) to save on production costs. Through cross licensing agreements, Cyrix and Rise may soon introduce their own Socket 370 compatible processors.

Slot 2 is another Intel proprietary socket, and is used only for their high-end Xeon processor line. The limited market for these items, as well as Intel's dominance in it has discouraged anyone from competing at this level - until now. AMD has come up with their own high-end design, which is called Slot A, and will be used only for their soon-to-be-released Athlon processor (formerly called K7). Those wishing to upgrade to this processor will be required to purchase a compatible motherboard.