In most computing contexts, PCI stands for peripheral component interconnect, a local bus standard developed by Intel. Although PCI buses are no longer the standard, at one time they used 47 pins to connect sound cards, network cards, and video cards to a computer. They were available in 32- or 64-bit versions and able to run at clock speeds of either 33 or 66 MHz. (A 32-bit PCI bus running at 33 MHz would yield a throughput rate of 133 MBps.)
PCI was commonly found in computers manufactured between 1995 and 2005, and many third parties relied on PCI buses to leverage the Plug n Play (PnP) feature of Windows 95 and early Apple Computers. PCI’s competitors at the time, Industry Standard Architecture (ISA) and VESA cards, were comparatively much slower and ultimately fell into obsolescence.
PCI is also an abbreviation for the Payment Card Industry. In this context, PCI refers to the development, management, education, and awareness of regulations related to credit and debit cards. The PCI Security Standards Council (PCI SSC) is the governing organization that has published and enforced the PCI Data Security Standards (PCI-DSS) since 2006. Members of the PCI SSC include Visa, Mastercard, American Express, Discover, and JCB.