Glossary

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AIP – Archival Information Package – A package designated for a digital archive, which includes not only digital content information but also preservation description information area such as a home, school, computer laboratory, or office building using network media.

Bit depth In computing, the number of bits used to represent a discrete item, using a coding system based on numeric values. In digital imaging, the number of bits used to represent a pixel (at least 15 bits for digital video and 24 bits to produce full colour in RGB – 8 bits per colour, red, green and blue, for a total of 16.7 millions of colours; for digital prints, that use 4 colours – Cyan, Magenta, Yellow and Black –, the bit depth is 32, or 4 x 8 bits).

Born digital Files that have been created by using a digital device, or through the use of a software. “Born digital” stands therefore as an opposite to “digitised”, where an analogue object or a signal has been turned into a digital file.

Copyright The exclusive legal right, given to an originator or an assignee to print, publish, perform, film, or record literary, artistic, or musical material, and to authorise others to do the same. A particular literary, artistic, or musical work can be covered by copyright. The copyright over a given work lasts for a period of 70 years following the death of the producer of the work. It covers the right to reproduce the work in any form, including in a database that has a public access (for instance, via the Internet).

Colour space A device colour space describes the range of colours, or gamut, that a camera can see, a printer can print, or a monitor can display. Editing colour spaces, such as Adobe RGB or sRGB, are device-independent. They allow to edit images in a controlled, consistent manner.

Calibration Calibration is part of colour management. It is the process that consists in measuring the accuracy of each device being used within the digitisation workflow (monitors, printers), and recording its behaviour.

Data compression Data compression implies reducing the volume of a given file by using compression algorithms. While it usually results in a loss in quality of the reduced file, there are lossless formats – as opposed to lossy – that allow a conversion from one format to another that does not result in the loss of data or information.

DCA – Digitising Contemporary Art

Digitise To convert (pictures or sound) into a digital form that can be processed by a computer. Digital preservation Digital preservation consists of maintaining in a condition that is suitable for use those files that have been produced through a digitisation process, or that are digital born. One should consider the alteration of the digital object itself (the “bit rot”), but also the technological environment in which the object was produced, with its evolution and obsolescence cycle. The Library of Congress (USA) has established the National Digital Information Infrastructure and Preservation Program, while the The Digital Preservation Coalition focuses on the preservation of digital resources in the UK.

DIP – Dissemination Information Package – The AIP becomes a DIP when the end-user or consumer requests a package's content information drives will typically be nominated with a letter followed by colon, such as C: or similar.

Distribution Copies Distribution files satisfy only limited researcher needs, and are not intended to substitute the original record if the original is damaged, destroyed, or not retained. Distribution files are retained only as long as needed to satisfy a specific distribution need. They are not actively managed over the long term. Distribution copies are generally derived from preservation master or reproduction master files. However, some classes of distribution files are direct captures from the source object and have no parent master file.

DROID – Digital Record Object Identification – Tool for verifying files and their format energy, as soon as the disks are not actively accessed.

HDD – Hard Disk Drive

I/O – Input/output

ISO – International Organization for Standardization

JBoD - Just a Bunch of Disks, see more in 3. Server Systems under Hard disk drives

JHOVE – Jstor/Harvard Object Validation Environment – Tool for verifying files and making metadata.

LAN - Local Area Network is a computer network that interconnects computers in a limited area such as a home, school, computer laboratory, or office building using network media.

LTO – Linear Tape Open (Archival tape)

Metadata Structured data about a physical or a digital object. The most important categories of metadata are the descriptive metadata (identification and location of the object), the structural metadata (used to describe relationships between an object's component parts), the technical metadata (information about the creation of the object), and the administrative metadata (about the management of the object).

MAID - Massive Array of Idle Disks, storage technology like RAID, but with energy management. Instead of the HDD being constantly on, the MAID turns them off to save

MARC – Machine-Readable Cataloguing – Metadata standard

METS – Metadata Encoding and Transmission Standard – Metadata structural standard

MLC flash - Multi-Level Cell, a technology of solid-state drives that can contain several bits

MODS – Metadata Object Description Schema – Metadata standard

NAS - Network Attached Storage, a NAS server is a preconfigured file server with internal network explained).

Nodes - In a network, a node is a connection point, either a redistribution point or an end point for data transmissions. In general, a node has a programmed or engineered capacity to recognise and process or forward transmissions to other nodes

OAIS – Open Archival Information System – Model for archival preservation storage and components needed for ideal preservation of digital content

OCR – Optical Character Recognition

Offsite - Any digital content that is stored on storage media that is not connected to the main headquarters of an institution.

Onsite - Any digital content located in-house, that is accessible from any computer at a workplace

Partition - The division of a hard disk or a tape to create an appearance of having separate

PCM – Pulse Code Modulation is a method used to digitally represent sampled analogue signals, the higher the sample rate the better the digital sound represents the original analogue signal

PDI – Preservation Description Information – Information package needed for preserving a given digital object for the long-term

PID – Persistent IDentifier, used for preserving links to digital or analogue objects

Pixels Stands for "picture element; any one of the dots of uniform illumination that comprise the image on a television screen or computer monitor in the aggregate. Pixels may be binary (black and white) or multi-valued to display colours or gradations of a grey scale. A pixel on a colour screen is a combination of three dots--blue, green, and red--called subpixels. The more pixels per inch, the better the resolution of the bitmap or screen.

Public domain Works in the public domain are those whose intellectual property rights have expired, which means that they are unavailable for private ownership and are available for public use. These rights are country-based and vary: a work may be subject to rights in one country and not in another. Most of the time, these rights extend up to 70 years after the creator’s death.

PREMIS – PREservation Metadata: Implemented Strategies – Data Dictionary developed by a group from the Library of Congress, US

RAID - Redundant Array of Independent Disks, originally Redundant Array of Inexpensive Disks, is a storage technology that combines multiple disk drive components into a logical unit. Data is distributed across the drives in one of several ways called "RAID levels”.

Resolution Refers to the density of the image. It is expressed as the number of pixels (PPI, pixels per inch) for a screen image, or the number of dots (DPI, dots per inch) for a printed image. The more units, the higher the resolution and the sharper the image.

RDF – Resource Description Framework

SSD – Solid State Drive

SAN - Storage Area Network is an advanced network connecting storage devices to servers, making the devices appear like locally attached disks to the operating system.

SAS – Serial Attached SCSI is a network that moves data to and from computer storage devices with the help of SCSI technology.

SATA - Serial Advanced Technology Attachment, is one cable containing a minimum of four wires that creates a point-to-point interface on a hard disk.

SCSI - Small Computer System Interface, see more in Hard disk drives

Server - A computer or computer program that manages access to a centralised resource or service in a network.

SIP – Submission Information Package – The information package made by the producer, before it is made into an AIP

SLC flash - Single-Level Cell, is a technology of solid state drives, where one single bit is stored on one single cell in a microchip.

TAR - Tape Archive, file format and software for writing and extracting files from magnetic tapes. TAR can also be used for indexing tapes, but it is not a strong part.

TCO - Total Cost of Ownership, the cost not only of purchasing equipment but also of energy consumption and renewal.

Transfer rate - The time it takes for data to be read or written onto the media (whether a tape, hard disk or other storage device), the transfer rate is measured in MB per second.

WORM - Write Once Read Many, a technology that ensures that data on a HDD, magnetic tape or a DVD/CD cannot be overwritten again, but can still be read repeatedly.

XML – eXtensible Mark-up Language - Standard mark-up language, combines text and extra information about the text

References