Peripheral Component Interconnect in the context of PCIe

In telecommunication and data transmission, serial communication is the process of sending data one bit at a time, sequentially, over a communication channel or computer bus. This is in contrast to parallel communication, where several bits are sent as a whole, on a link with several parallel channels.

Serial communication is used for all long-haul communication and most computer networks, where the cost of cable and difficulty of synchronization make parallel communication impractical. Serial computer buses have become more common even at shorter distances, as improved signal integrity and transmission speeds in newer serial technologies have begun to outweigh the parallel bus's advantage of simplicity (no need for serializer and deserializer, or SerDes) and to outstrip its disadvantages (clock skew, interconnect density). The migration from PCI to PCI Express (PCIe) is an example.

PC Card is a technical standard specifying an expansion card interface for laptops and PDAs. The PCMCIA originally introduced the 16-bit ISA-based PCMCIA Card in 1990, but renamed it to PC Card in March 1995 to avoid confusion with the name of the organization. The CardBus PC Card was introduced as a 32-bit version of the original PC Card, based on the PCI specification. CardBus slots are backward compatible, but older slots are not forward compatible with CardBus cards.

Although originally designed as a standard for memory-expansion cards for computer storage, the existence of a usable general standard for notebook peripherals led to the development of many kinds of devices including network cards, modems, and hard disks.

Sound Blaster X-Fi is a lineup of sound cards in Creative Technology's Sound Blaster series.

In computing, an expansion card (also called an expansion board, adapter card, peripheral card or accessory card) is a printed circuit board that can be inserted into an electrical connector, or expansion slot (also referred to as a bus slot) on a computer's motherboard (see also backplane) to add functionality to a computer system. Sometimes the design of the computer's case and motherboard involves placing most (or all) of these slots onto a separate, removable card. Typically such cards are referred to as a riser card in part because they project upward from the board and allow expansion cards to be placed above and parallel to the motherboard.

Expansion cards allow the capabilities and interfaces of a computer system to be extended or supplemented in a way appropriate to the tasks it will perform. For example, a high-speed multi-channel data acquisition system would be of no use in a personal computer used for bookkeeping, but might be a key part of a system used for industrial process control. Expansion cards can often be installed or removed in the field, allowing a degree of user customization for particular purposes. Some expansion cards take the form of "daughterboards" that plug into connectors on a supporting system board.

In computing, a peripheral bus is a computer bus designed to support computer peripherals like printers and hard drives. The term is generally used to refer to systems that offer support for a wide variety of devices, like Universal Serial Bus, as opposed to those that are dedicated to specific types of hardware. Serial AT Attachment, or SATA is designed and optimized for communication with mass storage devices.

This usage is not universal, some definitions of peripheral bus include any bus that is not a system bus, including examples like PCI. Others treat PCI and similar systems as a third category, the expansion bus.