Peripheral Component Interconnect -or- Payment Card Industry
As Peripheral Component Interconnect, a PCI is a local bus standard developed by Intel Corporation. Most modern PCs include a PCI bus in addition to a more general ISA expansion bus. It is believed that PCI will eventually supplant ISA entirely (and VESA, EISA, and VLB). PCI Version 1.0 is a 32-bit bus that runs at a clock speed of 33 MHz. This yields a throughput rate of 132 megabytes per second. PCI 2.0 is a 64-bit bus running at a clock speed of 66 MHz. Although it was developed by Intel, PCI is not tied to any particular family of microprocessors. In fact, in a strict sense, it is not a local bus at all, because it does not connect directly with the microprocessor. For this reason, some experts refer to it as a "mezzanine bus."
As Payment Card Industry, PCI implements DSS (Data Security Standard), a standard in security practices for e-commerce.