Hard disk in the context of Galvanometer

Disc and disk are both variants of the English word for objects of a generally thin and cylindrical geometry. The differences in spelling correspond both with regional differences and with different senses of the word. For example, in the case of flat, rotational data storage media the convention is that the spelling disk is used for magnetic storage (e.g., hard disks) while disc is used for optical storage (e.g., compact discs, better known as CDs). When there is no clear convention, the spelling disk is more popular in American English, while the spelling disc is more popular in British English.

Magnetic storage or magnetic recording is the storage of data on a magnetized medium. Magnetic storage uses different patterns of magnetisation in a magnetizable material to store data and is a form of non-volatile memory. The information is accessed using one or more read/write heads.

Magnetic storage media, primarily hard disks, are widely used to store computer data as well as audio and video signals. In the field of computing, the term magnetic storage is preferred and in the field of audio and video production, the term magnetic recording is more commonly used. The distinction is less technical and more a matter of preference. Other examples of magnetic storage media include floppy disks, magnetic tape, and magnetic stripes on credit cards.

A video camera is an optical instrument that captures videos, as opposed to a movie camera, which records images on film. Video cameras were initially developed for the television industry but have since become widely used for a variety of other purposes.

Video cameras are used primarily in two modes. The first, characteristic of much early broadcasting, is live television, where the camera feeds real time images directly to a screen for immediate observation. A few cameras still serve live television production, but most live connections are for security, military/tactical, and industrial operations where surreptitious or remote viewing is required. In the second mode the images are recorded to a storage device for archiving or further processing; for many years, videotape was the primary format used for this purpose, but was gradually supplanted by optical disc, hard disk, and then flash memory. Recorded video is used in television production, and more often surveillance and monitoring tasks in which unattended recording of a situation is required for later analysis.

A hard disk recorder (HDR) is a system that uses a high-capacity hard disk to record digital audio or digital video. Hard disk recording systems represent an alternative to reel-to-reel audio tape recording and video tape recorders, and provide non-linear editing capabilities unavailable using tape recorders. Audio HDR systems, which can be standalone or computer-based, are typically combined with provisions for digital mixing and processing of the audio signal to produce a digital audio workstation (DAW).

Direct-to-disk recording (DDR) refers to methods which may also use optical disc recording technologies such as DVD, and Compact disc.

Random-access memory (RAM; /ræm/) is a form of electronic computer memory that can be read and changed in any order, typically used to store working data and machine code. A random-access memory device allows data items to be read or written in almost the same amount of time irrespective of the physical location of data inside the memory, in contrast with other direct-access data storage media (such as hard disks and magnetic tape), where the time required to read and write data items varies significantly depending on their physical locations on the recording medium, due to mechanical limitations such as media rotation speeds and arm movement.

In modern technology, random-access memory takes the form of integrated circuit (IC) chips with MOS (metal–oxide–semiconductor) memory cells. RAM is normally associated with volatile types of memory where stored information is lost if power is removed. The two main types of volatile random-access semiconductor memory are static random-access memory (SRAM) and dynamic random-access memory (DRAM).

Perpendicular recording (or perpendicular magnetic recording, PMR), also known as conventional magnetic recording (CMR), is a technology for data recording on magnetic media, particularly hard disks. It was first proven advantageous in 1976 by Shun-ichi Iwasaki, then professor of the Tohoku University in Japan, and first commercially implemented in 2005. The first industry-standard demonstration showing unprecedented advantage of PMR over longitudinal magnetic recording (LMR) at nanoscale dimensions was made in 1998 at IBM Almaden Research Center in collaboration with researchers of Data Storage Systems Center (DSSC) – a National Science Foundation (NSF) Engineering Research Center (ERCs) at Carnegie Mellon University (CMU).

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.

In computing (specifically data transmission and data storage), a block, sometimes called a physical record, is a sequence of bytes or bits, usually containing some whole number of records, having a fixed length; a block size. Data thus structured are said to be blocked. The process of putting data into blocks is called blocking, while deblocking is the process of extracting data from blocks. Blocked data is normally stored in a data buffer, and read or written a whole block at a time. Blocking reduces the overhead and speeds up the handling of the data stream. For some devices, such as magnetic tape and CKD disk devices, blocking reduces the amount of external storage required for the data. Blocking is almost universally employed when storing data to 9-track magnetic tape, NAND flash memory, and rotating media such as floppy disks, hard disks, and optical discs.

Most file systems are based on a block device, which is a level of abstraction for the hardware responsible for storing and retrieving specified blocks of data, though the block size in file systems may be a multiple of the physical block size. This leads to space inefficiency due to internal fragmentation, since file lengths are often not integer multiples of block size, and thus the last block of a file may remain partially empty. This will create slack space. Some newer file systems, such as Btrfs and FreeBSD UFS2, attempt to solve this through techniques called block suballocation and tail merging. Other file systems such as ZFS support variable block sizes.

The Xbox is a home video game console manufactured by Microsoft. It is the first installment in the Xbox series of video game consoles. It was released on November 15, 2001, in North America, followed by Australia, Europe and Japan in 2002. As a sixth-generation console, it competed with Sony's PlayStation 2, Sega's Dreamcast and Nintendo's GameCube. It was also the first major console produced by an American company since the release of the Atari Jaguar in 1993.

The console was announced in March 2000. With the release of the PlayStation 2, which featured the ability to playback CD-ROMs and DVDs in addition to playing games, Microsoft became concerned that game consoles would threaten the personal computer as an entertainment device for living rooms. Whereas most previous games consoles used specially designed hardware, the Xbox was built around standard PC components. It uses variations of Microsoft Windows and DirectX as its operating system to support games and media playback, and is powered by a Intel Pentium III CPU and an Nvidia GeForce 3-based GPU. The Xbox was the first console to feature a built-in hard disk. The console was designed to support broadband connectivity to the Internet via an integrated Ethernet port and Xbox Live, a fee-based online gaming service that launched in 2002. The popularity of the system's blockbuster titles such as Bungie's Halo 2 (2004) contributed to the popularity of first-person shooters and online console gaming.

Zune was a brand of digital media products and services that was marketed by Microsoft from November 2006 until it was discontinued in June 2012. Zune consisted of a line of portable media players, a music subscription service known as Zune Music Pass plus Zune Marketplace for music, TV and movies, streaming services for the Xbox 360 game console, and the Zune software media player for Windows computers which also acted as desktop sync software for Windows Phone.

Zune started and revolved around its line of portable media players (PMP) created in cooperation with Toshiba. Microsoft aimed to challenge and beat Apple, whose iPod line held an enormous market share. Three hard disk players ranging from 30 GB to 120 GB were released, alongside six flash players. However, its overall market share in the U.S. remained low, well below Apple and also lagged behind the SanDisk Sansa and Creative Zen. Microsoft discontinued all Zune hardware in October 2011. Zune digital content distribution continued until 2012, when it was replaced by the Xbox Music and Xbox Video brands.

Hibernation (also known as suspend to disk, or Safe Sleep on Macintosh computers) in computing is powering down a computer while retaining its state. When hibernation begins, the computer saves the contents of its random access memory (RAM) to a hard disk or other non-volatile storage. When the computer is turned on the RAM is restored and the computer is exactly as it was before entering hibernation. Hibernation was first implemented in 1992 and patented by Compaq Computer Corporation in Houston, Texas.

Microsoft's Windows 8, Windows 8.1, Windows 10 and Windows 11 employ a type of hibernation (Fast Startup) by default when shutting down.

A head crash is a hard-disk failure that occurs when a read–write head of a hard disk drive makes contact with its rotating platter, slashing its surface and permanently damaging its magnetic media. It is difficult to recover data from a head crashed drive. It is most often caused by a sudden severe motion of the disk, for example the jolt caused by dropping a laptop to the ground while it is operating or physically shocking a computer. Laptop 2.5" drives are significantly more likely to have a head crash due to their mobile nature despite having higher shock resistance than 3.5" desktop drives. Desktop drives being larger are more prone to damage if dropped but are usually in one place like in a computer/server so they are overall less likely to have a head crash.