Archive Guide Glossary

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There are currently 38 names in this directory.
API (Application Programming Interface)

A protocol that specifies a way for a software application to communicate and integrate with a program that provides a service. Google provides APIs, for example, so that people can use its data, such as location data from Google Maps or video data from YouTube, in their applications.


Backup

A copy of data, stored in a secondary location, which is used to restore data in the primary storage location that is corrupted or lost. Restoring involves copying data from the backup to the primary storage to replace the corrupted or lost files. Backing up is a storage strategy that allows you to recover from data loss.


Checksum

See “Hash Value”

Hash Function

An algorithm that computes a hash value or checksum from any set of data, like a file. Common hash functions include MD5 and SHA1. Hash functions are used to check file integrity and for security purposes.

CLI (Command-Line Interface)

A way of interacting with a computer program which involves typing lines of text in a command-line shell. Some programs are only available with command-line interfaces, which facilitate their automation and use in programming scripts. However, command-line interfaces can be harder for casual computer users to interact with than graphical user interfaces (GUI), which use windows, icons, menus, and pointers.

Command-Line Interface

A way of interacting with a computer program which involves typing lines of text in a command-line shell. Some programs are only available with command-line interfaces, which facilitate their automation and use in programming scripts. However, command-line interfaces can be harder for casual computer users to interact with than graphical user interfaces (GUI), which use windows, icons, menus, and pointers.

Codec

A codec is software that can encode/compress and decode/decompress digital files, including video files. Common video codecs include H.264/MPEG-4 AVC, MPEG-2, and DV. A video stream can be encoded with one of these codecs and contained in a file format like AVI or Quicktime.

File Format

The specification by which a digital file is encoded. Some file formats are designed to store particular kinds of data while others are more like containers that can hold many kinds of data. Common video file formats like Quicktime (.mov), AVI, and mp4 are container formats that contain video and audio streams, metadata, subtitle tracks, etc.

Copyright

A legal protection intended to give the creator of original work exclusive rights to their work for a designated length of time. It gives the creator the exclusive right to copy, use, adapt, show, and distribute their own work, and the right to determine who else can copy, use, adapt, show, and distribute the work.


Data Dictionary

A document that explicitly describes metadata structure and rules so that all catalogers input metadata in a catalog consistently. A data dictionary may also specify your controlled vocabularies. Data dictionaries do not contain actual metadata, only the instructions needed to create your metadata.

Metadata

Any information about a video: from technical information embedded in the file that allows the video to function, such as format and duration, to descriptive information about the content to help you understand or find it--such as keywords, security restrictions, geographic locations, and so on. Metadata is critical to any future use, and is important throughout the archiving process. Despite what is sometimes said, images almost never speak for themselves. They require context and description to make sense, to corroborate their factuality, and to be accessible beyond one person’s memory or desktop. Metadata can be automatically generated and embedded in the file, such as with technical metadata, or it can be manually recorded on an external medium, such as with descriptions, security flags, and keywords in a database. Metadata capture sometimes needs to be manually enabled on your device, such as with GPS or location services.

Controlled Vocabulary

A predefined list of terms used to ensure consistency in cataloging. Since there is usually more than one way to describe or refer to a concept, choosing one term eliminates guesswork and circumvents the normal ambiguities of language (and spelling). Imagine searching for “Doctors” only to later learn that some records use the term “Physicians”. Consistent vocabularies increase the findability of records.

Data Model

A description of the way that data is structured in a database. It can define what types of things the data describe, what types of data are included in the descriptions, and how different types of things relate to each other.


Derivative

A copy of a video generated from a master that is usually in a different format and of lower quality than the master. Derivatives can be made for various uses, such as web upload or DVD.

Master

The earliest generation or highest-quality output of a video from which duplicates are made.

Digital Video

An audiovisual signal that is represented in discrete bits, as opposed to a continuous analog signal. Analog video, such as Hi8 or VHS, is obsolete; all video cameras available today record digital video. Digital video can be tape-based (e.g. miniDV, HDV) or file-based (e.g. .mov, .avi). In this guide, we focus on file-based digital video, as tape-based digital video is mostly obsolete.

Obsolescence

The process of becoming out-of-date and unsupported by available technology. Video cameras, video formats, storage media and storage devices, can all become obsolete over time. The obsolete technology is functional but is unusable because the other technologies they depend on no longer support them. An old video camera, for example, may not be able to plug into new computers, or an old video format might not be playable on new desktop video players.

Download

To receive data from a remote computer system and save it in a local computer system. The inverse of download is "upload."

Upload

To send data from a local computer system to a remote one. The inverse of upload is "download."

EDL (Edit Decision List)

A document used in video post-production that contains a list of clips used in an edited video. EDLs originate from older film and video workflows when editing was a two stage process. Today, they can be used to move editing projects from one software or system to another. EDLs also provide useful documentation, showing what source files were used to create an edited video.


Embedded Metadata

Metadata that is stored within the digital object it describes. Some embedded metadata, such as file size, are essential to the functioning of the file, and are always written to the file by the device or software system. Other embedded metadata are non-essential and can be optionally added (e.g. rights information). Embedded metadata is not guaranteed to be accurate—for example, if your camera is set to the wrong date. Embedded metadata stay with the digital object as long as the object is intact, but can be intentionally stripped or altered. Embedded metadata can be lost if a file is transcoded to another format.

Metadata

Any information about a video: from technical information embedded in the file that allows the video to function, such as format and duration, to descriptive information about the content to help you understand or find it--such as keywords, security restrictions, geographic locations, and so on. Metadata is critical to any future use, and is important throughout the archiving process. Despite what is sometimes said, images almost never speak for themselves. They require context and description to make sense, to corroborate their factuality, and to be accessible beyond one person’s memory or desktop. Metadata can be automatically generated and embedded in the file, such as with technical metadata, or it can be manually recorded on an external medium, such as with descriptions, security flags, and keywords in a database. Metadata capture sometimes needs to be manually enabled on your device, such as with GPS or location services.

Encryption

The process of encoding your files using a cryptographic algorithm so that only authorized parties with a “key” (e.g. a password) can decrypt them. The two main types of encryption are symmetric-key and public-key. Symmetric-key encryption uses the same key, or password, to encrypt and decrypt information. Public-key encryption uses one key to encrypt, and a different one to decrypt, and is more secure.


Entity

In data models, an entity is any "thing" that is identified and described with data. For example, if a database keeps track of the model, year, and license plates of all the cars in a sales lot, each car is an entity.


Fat32

A computer file system developed by Microsoft that can be read and written to by Mac and Windows devices. Many USB flash drives come formatted as FAT32. The maximum file size on a FAT32-formatted volume is 4GB, which may not meet the needs of large video files.


File Format

The specification by which a digital file is encoded. Some file formats are designed to store particular kinds of data while others are more like containers that can hold many kinds of data. Common video file formats like Quicktime (.mov), AVI, and mp4 are container formats that contain video and audio streams, metadata, subtitle tracks, etc.


Finding Aid

A document that contains information about a specific collection within an archive. It is a simple way for users to determine if the content in a collection is relevant to their research. The structure of finding aids differ depending on the material being described; they can contain detailed content lists, a description of the scope of the collection, biographical and historical information, and even restrictions on use or access to the content.

Archive

An organization made up of people and systems responsible for preserving records and documents of enduring value and making them available to a designated community. Archives are sometimes parts of larger organizations, such as universities, public libraries, media centers, or museums.

Firewire

An interface standard for transferring data between digital devices, especially audio and video equipment. Developed by Apple in the 1990s, FireWire is becoming obsolete.

Obsolescence

The process of becoming out-of-date and unsupported by available technology. Video cameras, video formats, storage media and storage devices, can all become obsolete over time. The obsolete technology is functional but is unusable because the other technologies they depend on no longer support them. An old video camera, for example, may not be able to plug into new computers, or an old video format might not be playable on new desktop video players.

FTP (File Transfer Protocol)

A network protocol for transferring files between two points over the Internet. Users use FTP client applications (e.g. FileZilla) to communicate with an FTP server.


GUI (Graphical User Interface)

A way of interacting with a computer program that involves using windows, icons, menus, and pointers. Most computer users are familiar with graphical user interfaces. GUIs can be easier for casual users to interact with than command-line interfaces (CLI), which require commands to be typed as lines of text.

Command-Line Interface

A way of interacting with a computer program which involves typing lines of text in a command-line shell. Some programs are only available with command-line interfaces, which facilitate their automation and use in programming scripts. However, command-line interfaces can be harder for casual computer users to interact with than graphical user interfaces (GUI), which use windows, icons, menus, and pointers.

Hash Function

An algorithm that computes a hash value or checksum from any set of data, like a file. Common hash functions include MD5 and SHA1. Hash functions are used to check file integrity and for security purposes.

Hash Function

An algorithm that computes a hash value or checksum from any set of data, like a file. Common hash functions include MD5 and SHA1. Hash functions are used to check file integrity and for security purposes.

Integrity

The quality of being whole, unaltered, and uncorrupted. A file that is not intact may not be usable or may have decreased informational and evidential value. Videos files can lose their integrity if they are accidentally mishandled, deliberately tampered with, or if data corruption occurs in transfer or storage due to hardware or software malfunction. The best way to ensure integrity is to establish a system to check file fixity regularly (e.g. by computing hashes and checking them against a registry of previously computed hashes) and to restore any corrupted files from an intact copy.

Hash Value

The string of alphanumeric characters that results from running a hash function algorithm on data or a file.  The hash value of a file will always remain the same as long as the file is unchanged, so it can be used to identify altered, corrupted, and duplicated files.

Hash Function

An algorithm that computes a hash value or checksum from any set of data, like a file. Common hash functions include MD5 and SHA1. Hash functions are used to check file integrity and for security purposes.

HFS

A computer file system developed by Apple that can only be read by Windows devices using special software. Windows devices cannot write to HFS-formatted volumes.


Intellectual Property

A legal concept that refers to creative works for which exclusive rights are recognized. Common types of IP rights include copyright, trademarks and patents.


Malware

A term derived from "malicious software," and that refers to all computer viruses, worms, Trojans, and spyware.


Metadata Standard

A published document that describes how to create, use, and interpret metadata in a specific domain or for a specific purpose, which is intended to establish a common understanding among its users. A metadata standard defines the structure and meaning of its acceptable data elements, rules, and values. Many communities, including broadcasters, social scientists, and art museums, publish metadata standards to meet their descriptive needs.

Metadata

Any information about a video: from technical information embedded in the file that allows the video to function, such as format and duration, to descriptive information about the content to help you understand or find it--such as keywords, security restrictions, geographic locations, and so on. Metadata is critical to any future use, and is important throughout the archiving process. Despite what is sometimes said, images almost never speak for themselves. They require context and description to make sense, to corroborate their factuality, and to be accessible beyond one person’s memory or desktop. Metadata can be automatically generated and embedded in the file, such as with technical metadata, or it can be manually recorded on an external medium, such as with descriptions, security flags, and keywords in a database. Metadata capture sometimes needs to be manually enabled on your device, such as with GPS or location services.

NAS (Network Attached Storage)

Computer data storage that is accessed through a network. A NAS appliance is a computer that is specially designed to store and serve files over a network.


NTFS

A computer file system developed by Microsoft that is read-only on Macs. Macs can write to NTFS-formatted volumes only with special software.


Offload

To copy media from a camera or memory card to a storage device connected to a computer.


Petabyte

A unit of measure for data. One petabyte (PB) is equivalent to 1,000 terabytes (TB), or 1,000,000 gigabytes (GB).


Preservation

A system that acquires, stores, monitors, preserves, and provides access to its resources, run by an organization committed to providing long-term access to authenticated content to its users. A repository requires significant infrastructure to build and maintain.

Preservation

The process of ensuring the long-term accessibility of authenticated content. Digital preservation involves preventing loss or damage to digital objects, and extending their existence beyond the lifespan of their storage media or technology. Preservation requires ongoing resources, commitment and actions.

Authenticity

The quality of being genuine, not fake or counterfeit, and free from tampering. Authenticity means that an object was actually created by the person represented as its creator, and that it was actually created at the time and place that is represented as its time and place of creation. Video footage that has been manipulated or altered but is represented as if it had not been, for example, is not authentic. To authenticate a video means to verify the relationship between it and its creator and point of creation. Documentation about who created something, when and where it was created, and the chain of custody can provide a starting point for this authentication process.

RAID (Redundant Array of Independent (or Inexpensive) Disks)

A storage technology that combines multiple hard drives together to provide fault tolerance and better performance. Data is spread out across the drives, along with additional calculated data, so that data can be re-generated if part of the array fails. RAID protects you against data loss in the case of hardware failure. Unlike backup, RAID does not offer protection against file corruption or deletion, or data loss to malware, theft, or natural disaster.

Backup

A copy of data, stored in a secondary location, which is used to restore data in the primary storage location that is corrupted or lost. Restoring involves copying data from the backup to the primary storage to replace the corrupted or lost files. Backing up is a storage strategy that allows you to recover from data loss.

Malware

A term derived from "malicious software," and that refers to all computer viruses, worms, Trojans, and spyware.

Repository

A system that acquires, stores, monitors, preserves, and provides access to its resources, run by an organization committed to providing long-term access to authenticated content to its users. A repository requires significant infrastructure to build and maintain.

Preservation

The process of ensuring the long-term accessibility of authenticated content. Digital preservation involves preventing loss or damage to digital objects, and extending their existence beyond the lifespan of their storage media or technology. Preservation requires ongoing resources, commitment and actions.

Authenticity

The quality of being genuine, not fake or counterfeit, and free from tampering. Authenticity means that an object was actually created by the person represented as its creator, and that it was actually created at the time and place that is represented as its time and place of creation. Video footage that has been manipulated or altered but is represented as if it had not been, for example, is not authentic. To authenticate a video means to verify the relationship between it and its creator and point of creation. Documentation about who created something, when and where it was created, and the chain of custody can provide a starting point for this authentication process.

SAN (Storage Area Network)

A dedicated network of storage devices shared among multiple servers, designed for fast access and large data transfers.


Synchronization

The process of ensuring that computer files in one location are copied to one or more other locations on a regular basis. Synchronization is also referred to as mirroring or replication. Unlike backup, synchronization does not allow you to go "back in time" to recover lost or altered files.

Backup

A copy of data, stored in a secondary location, which is used to restore data in the primary storage location that is corrupted or lost. Restoring involves copying data from the backup to the primary storage to replace the corrupted or lost files. Backing up is a storage strategy that allows you to recover from data loss.

Transcode

To re-encode a digital file to a different encoding scheme, such as converting an H.264/MPEG-4 AVC video to Apple ProRes. Transcoding is usually done when a video’s encoding is not supported by the system that needs to use it. Transcoding fundamentally alters the file, although lossless methods can allow the original data to be reconstructed from the transcoded data.


Upload

To send data from a local computer system to a remote one. The inverse of upload is "download."

Download

To receive data from a remote computer system and save it in a local computer system. The inverse of download is "upload."

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