Sound card in the context of Sound Blaster X-Fi

Computer hardware includes the physical parts of a computer, such as the central processing unit (CPU), random-access memory (RAM), motherboard, computer data storage, graphics card, sound card, and computer case. It includes external devices such as a monitor, mouse, keyboard, and speakers.

By contrast, software is a set of written instructions that can be stored and run by hardware. Hardware derived its name from the fact it is hard or rigid with respect to changes, whereas software is soft because it is easy to change.

An output device is any piece of computer hardware that converts information or data into a human-perceptible form or, historically, into a physical machine-readable form for use with other non-computerized equipment. It can be text, graphics, tactile, audio, or video. Examples include monitors, printers and sound cards.

In an industrial setting, output devices also include "printers" for paper tape and punched cards, especially where the tape or cards are subsequently used to control industrial equipment, such as an industrial loom with electrical robotics which is not fully computerized

In electronics, an analog-to-digital converter (ADC, A/D, or A-to-D) is a system that converts an analog signal, such as from fingers touching a touchscreen, sound entering a microphone, or light entering a digital camera, into a digital signal.

An ADC may also provide an isolated measurement such as an electronic device that converts an analog input voltage or current to a digital number representing the magnitude of the voltage or current. Typically the digital output is a two's complement binary number that is proportional to the input, but there are other possibilities.

In electronics, a digital-to-analog converter (DAC, D/A, D2A, or D-to-A) is a system that converts a digital signal into an analog signal. An analog-to-digital converter (ADC) performs the reverse function.

DACs are commonly used in music players to convert digital data streams into analog audio signals. They are also used in televisions and mobile phones to convert digital video data into analog video signals. These two applications use DACs at opposite ends of the frequency/resolution trade-off. The audio DAC is a low-frequency, high-resolution type, while the video DAC is a high-frequency low- to medium-resolution type.

ExpressCard, initially called NEWCARD, is an interface to connect peripheral devices to a computer, usually a laptop computer. The ExpressCard technical standard specifies the design of slots built into the computer and of expansion cards to insert in the slots. The cards contain electronic circuits and sometimes connectors for external devices. The ExpressCard standard replaces the PC Card (also known as PCMCIA) standards.

ExpressCards can connect a variety of devices to a computer including mobile broadband modems (sometimes called connect cards), IEEE 1394 (FireWire) connectors, USB connectors, Ethernet network ports, Serial ATA storage devices, solid-state drives, external enclosures for desktop-size PCI Express graphics cards and other peripheral devices, wireless network interface controllers (NIC), TV tuner cards, Common Access Card (CAC) readers, and sound cards.

A DJ mix, DJ mixset or DJ set is a sequence of musical tracks typically mixed together by a DJ to appear as one continuous track. DJ mixes are usually performed using a DJ mixer and multiple sounds sources, such as turntables, CD players, digital audio players or computer sound cards, sometimes with the addition of samplers and effects units, although it is possible to create one using sound editing software.

DJ mixing is significantly different from live sound mixing. Remix services were offered beginning in the late 1970s in order to provide music which was more easily beatmixed by DJs for the dancefloor. One of the earliest DJs to refine their mixing skills was DJ Kool Herc. Francis Grasso was the first DJ to use headphones and a basic form of mixing at the New York City nightclub Sanctuary. Upon its release in 2000, Paul Oakenfold's Perfecto Presents: Another World became the biggest-selling DJ mix album in the US.

An audio codec is a device or computer program capable of encoding or decoding a digital data stream (a codec) that encodes or decodes audio. In software, an audio codec is a computer program implementing an algorithm that compresses and decompresses digital audio data according to a given audio file or streaming media audio coding format. The objective of the algorithm is to represent the high-fidelity audio signal with a minimum number of bits while retaining quality. This can effectively reduce the storage space and the bandwidth required for transmission of the stored audio file. Most software codecs are implemented as libraries which interface to one or more multimedia players. Most modern audio compression algorithms are based on modified discrete cosine transform (MDCT) coding and linear predictive coding (LPC).

In hardware, audio codec refers to a single device that encodes analog audio as digital signals and decodes digital back into analog. In other words, it contains both an analog-to-digital converter (ADC) and digital-to-analog converter (DAC) running off the same clock signal. This is used in sound cards that support both audio in and out, for instance. Hardware audio codecs send and receive digital data using buses such as AC'97, SoundWire, I²S, SPI, I²C, etc. Most commonly the digital data is linear PCM, and this is the only format that most codecs support, but some legacy codecs support other formats such as G.711 for telephony.

PCI Express (Peripheral Component Interconnect Express), officially abbreviated as PCIe, is a high-speed standard used to connect hardware components inside computers. It is designed to replace older expansion bus standards such as PCI, PCI-X and AGP. Developed and maintained by the PCI-SIG (PCI Special Interest Group), PCIe is commonly used to connect graphics cards, sound cards, Wi-Fi and Ethernet adapters, and storage devices such as solid-state drives and hard disk drives.

Compared to earlier standards, PCIe supports faster data transfer, uses fewer pins, takes up less space, and allows devices to be added or removed while the computer is running (hot swapping). It also includes better error detection and supports newer features like I/O virtualization for advanced computing needs.

The game port is a device port that was found on IBM PC compatible and other computer systems throughout the 1980s and 1990s. It was the traditional connector for joystick input, and occasionally MIDI devices, until made obsolete by USB in the late 1990s.

Originally located on a dedicated Game Control Adapter expansion card, the game port was later integrated with PC sound cards, and still later on the PC's motherboard. During the transition to USB, many input devices used the game port and a USB adapter dongle was included for systems without a game port.

Software-defined radio (SDR) is a radio communication system where components that conventionally have been implemented in analog hardware (e.g. mixers, filters, amplifiers, modulators/demodulators, detectors, etc.) are instead implemented by means of software on a computer or embedded system.

A basic SDR system may consist of a computer equipped with a sound card, or other analog-to-digital converter, preceded by some form of RF front end. Significant amounts of signal processing are handed over to the general-purpose processor, rather than being done in special-purpose hardware (electronic circuits). Such a design produces a radio which can receive and transmit widely different radio protocols (sometimes referred to as waveforms) based solely on the software used.

Peripheral Component Interconnect (PCI) is a local computer bus for attaching hardware devices in a computer and is part of the PCI Local Bus standard. The PCI bus supports the functions found on a processor bus but in a standardized format that is independent of any given processor's native bus. Devices connected to the PCI bus appear to a bus master to be connected directly to its own bus and are assigned addresses in the processor's address space. It is a parallel bus, synchronous to a single bus clock.Attached devices can take either the form of an integrated circuit fitted onto the motherboard (called a planar device in the PCI specification) or an expansion card that fits into a slot. The PCI Local Bus was first implemented in IBM PC compatibles, where it displaced the combination of several slow Industry Standard Architecture (ISA) slots and one fast VESA Local Bus (VLB) slot as the bus configuration. It has subsequently been adopted for other computer types. Typical PCI cards used in PCs include: network cards, sound cards, modems, extra ports such as Universal Serial Bus (USB) or serial, TV tuner cards and hard disk drive host adapters. PCI video cards replaced ISA and VLB cards until rising bandwidth needs outgrew the abilities of PCI. The preferred interface for video cards then became Accelerated Graphics Port (AGP), a superset of PCI, before giving way to PCI Express.

The first version of PCI found in retail desktop computers was a 32-bit bus using a 33 MHz bus clock and 5 V signaling, although the PCI 1.0 standard provided for a 64-bit variant as well. These have one locating notch in the card. Version 2.0 of the PCI standard introduced 3.3 V slots, physically distinguished by a flipped physical connector to prevent accidental insertion of 5 V cards. Universal cards, which can operate on either voltage, have two notches. Version 2.1 of the PCI standard introduced optional 66 MHz operation. A server-oriented variant of PCI, PCI Extended (PCI-X) operated at frequencies up to 133 MHz for PCI-X 1.0 and up to 533 MHz for PCI-X 2.0. An internal connector for laptop cards, called Mini PCI, was introduced in version 2.2 of the PCI specification. The PCI bus was also adopted for an external laptop connector standard – the CardBus. The first PCI specification was developed by Intel, but subsequent development of the standard became the responsibility of the PCI Special Interest Group (PCI-SIG).