The carrier is a physically independent support for the information. The carrier is a media (ready for) carrying a representation of information. The representation can (could be) be analogue or digital. The digital carrier is limited by its ability to store a maximum number of bits. The representation can be spatial, temporal or spatio-temporal.
For example: A CD-R disk ready for engraving is a digital and spatial carrier.

Each of its physically bounded / limited parts of a carrier is a ‘carrier-component’.
For example: Each of the two face of a microgroove is a carrier-component. The independent digital carriers can store data in files and/or folders. The single layer of a DVD5 (4.7 GB) is one carrier. The two layers of a DVD9 (8,5 GB) is one carrier: each of the layers is a carrier-component. A book is a ‘carrier’ made of pages, each page being a ‘carrier-component’. 

A chained set of carriers is a ‘Carrier-Stream’. For example, the two faces of a microgroove, the two faces of a cassette tape. 

A chained set of media representing an ‘Opus’ is a clip. The clip is represented by a set of files (essence, controls and metadata). The representation of a ‘Opus-component’ is a ‘Clip-component’. A ‘Clip-stream’ is one representation of an ‘Opus-stream’. 

A ‘collection’ is any consistent set of information. In AXIS, a ‘collection’ is expressed as being one (or more) OPUS or Packages; a logical ‘collection’ is expressed as being one (or several) OPUS; a physical ‘collection’ is expressed a being one or several ‘packages’. 

The ‘containers’ are means to wrap and document in evidence one (or several) volume(s) in order to constitute one SIP or one AIP or one DIP. 

The ‘data elements’ are the elementary ‘data items’. Each ‘data element’ is defined in ontology, semantic, values, representation, presentation … according the relevant ISO standard. 

Any structured assembly of ‘data elements’. An occurrence of a ‘data base’ can be realized by any means. For instance, a simple XML file could represent a ‘data base’; a ‘data base’ could be represented as a fragment within a huge “Data Base Management System”. 

The representation of possible evidence: sound, video, picture, object … In its basic form, the ‘essence’ does not include metadata nor controls. However, some of the representation formats cover the facilities for including them within the file or the stream. 

A General Software Library is a product designed to be included as “Third Party Software” in a system. As example, the set of facilities for “source separation” or for the coding of files in the “MP3 format” from the “Broadcast Wave Format” could be designed in the form of a GSL. 

The reference model known under the “Open Archival Information Systems” is defined by two documents (one in English the other in French) available at www.ccsds.org. It defines a model for constructing “Information Systems” able at building archives and exploiting them. The model constructs, in a predictable way, the persistence and the interoperability of the archives. The OAIS is based on three content based interfaces named:

• SIP Submission Information Package
• AIP Archive Information Package
• DIP Dissemination Information Package 

An extension of the “Open Archival Information Systems” model in currently worked-out, namely by TITAN, within the current OAIS upgrade project of the CCSDS, aiming at covering the acquisition of contents and constructing the metadata, structure, projects, semantics, ontology, … associated with the essences representing the target content to be preserved and exploited. The acronym OAIS+ is often named “Open Assets Information Systems”. The OAIS+ covers three additional content based interfaces:

• OPR Original Physical Reality
• OPC Original on its Original Physical carrier
• OIP Original Information Package

These concepts are further explained here after.

An OPUS is a complete semantic item. The semantic item could include the ‘project’ managing the realization of the intention; the ‘resources’ required to realize it and the ‘results’ of the project. The OPUS is not packaged but could define a packaging. The OPUS is represented by files and folders independently of any carrier, volumes and packages.

An elementary part of an ‘opus’ such as each of the four movements, typically, of a string quartet or elementary thematic breaks within the chapters of a book.

An ‘opus stream’ is an ordered set of ‘opus’ such as each of the 32 sonatas of Ludwig van Beethoven.

The word “original” means the ‘package’ instance issued at creation time of the ‘package’. When the first issue has generated a set of package, each of the issued ‘packages’ is reputed being an original. Example: an engraving issued in 16 ‘trade-originals’ (marked 1/16 up to 16/16) and two ‘artist-proof-engravings’ (with one of them destroyed because badly processed) means 17 originals. See also the concepts of OPR, OPC and OIP in the OAIS+ model.

A ‘package’ is an ‘embodiment’ of information. A ‘package’ is a set of ‘volumes’ wrapped in a ‘container’.

A ‘profile’ is the definition of all what is specific to a particular vision, a particular way of modeling the target reality. A “Profile” is a coherent personalized representation. For example, a specific profile can be created for the “Tennis”, an other for the “Basket”, another for the “Weather forecast”, another for the “Classical music” … The instances of the profiles are hooked to the instance of a “Backbone”.

A ‘location’ in a stream: the location could be expressed in various ways (for example, time code, a tag or mark or chunk); metadata or synchronization could be connected to the point.

A ‘segment’ is a part of a stream defined by two ‘locations’; metadata or synchronization could be connected to the segment.

A ‘volume’ is the assembly data representing information expressed on one carrier. The data could be represented in analog form (a microgroove disk, for example) or in digital [ideally expressed according to standardized data-sets and formats (expressed according to a standardized character set) and included in files and folders (expressed in a standardized format).

A ‘volume stream’ is chained set of ‘volumes’.

A ‘wrapper’ is technology for bundling metadata, contents files and folders pertaining to an item (logical and/or physical). The current most used logical wrappers are ZIP, METS, MXF.
Remark : The capacity of integrating metadata or controls in the stream representing the contents is not considered as “wrapping”. For example, MPEG-4 allows that facility which is often used in broadcasted OAIS-DIP’s.