# Terminology

Author

  The person(s) or organization responsible for the creation of an EPUB Publication, which is not necessarily the creator of the content and resources it contains.

EPUB Container (or Container)

  The ZIP-based packaging and distribution format for EPUB Publications defined in [OCF3].

EPUB Content Document

  A Publication Resource that conforms to one of the EPUB Content Document definitions (XHTML or SVG).

  An EPUB Content Document is a Core Media Type, and may therefore be included in the EPUB Publication without the provision of fallbacks.

EPUB Navigation Document

  A specialization of the XHTML Content Document, containing human- and machine-readable global navigation information, conforming to the constraints expressed in EPUB Navigation Documents [ContentDocs30].

Scripted Content Document

  An EPUB Content Document that includes scripting or an XHTML Content Document that contains HTML5 forms elements.

  Refer to Scripted Content Documents [ContentDocs30] for more information.

SVG Content Document

  An EPUB Content Document conforming to the constraints expressed in SVG Content Documents [ContentDocs30].

XHTML Content Document

  An EPUB Content Document conforming to the profile of [HTML5] defined in XHTML Content Documents [ContentDocs30].

  XHTML Content Documents use the XHTML syntax of [HTML5].

Top-level Content Document

  An EPUB Content Document referenced directly from the spine

Core Media Type

  A set of Publication Resource types for which no fallback is required. Refer to Publication Resources for more information.

EPUB Publication (or Publication)

  A logical document entity consisting of a set of interrelated resources and packaged in an EPUB Container, as defined by this specification and its sibling specifications.

EPUB Reading System (or Reading System)

  A system that processes EPUB Publications for presentation to a User in a manner conformant with this specification and its sibling specifications.

Manifest

  A list of all Publication Resources that constitute the EPUB Publication.

  Refer to manifest for more information.

Manifestation

  The digital (or physical) embodiment of a work of intellectual content. Changes to the content such as significant revision, abridgement, translation, or the realization of the content in a different digital or physical form result in a new manifestation. There may be many individual but identical copies of a manifestation, termed 'instances' or 'items'. The ISBN is an example of a manifestation identifier, and is shared by all instances of that manifestation.

  All instances of a manifestation need not be bit-for-bit identical, as minor corrections or revisions are not judged to create a new manifestation or work.

Media Overlay Document

  An XML document that associates the XHTML Content Document with pre-recorded audio narration in order to provide a synchronized playback experience, as defined in [MediaOverlays30].

OCF Processor

  A software application that processes EPUB Containers according to this specification.

Package Document

  A Publication Resource carrying bibliographical and structural metadata about the EPUB Publication, as defined in Package Documents.

Package Identifier

  The Package Identifier allows any instance of an EPUB Publication to be compared against another to determine if they are identical, different versions of the same Manifestation, or unrelated.

  Refer to Package Identifier for more information.

Core Media Type Resource

  A Publication Resource that is a Core Media Type and may therefore be included in the EPUB Publication without the provision of fallbacks.

Publication Resource

  A resource that contains content or instructions that contribute to the logic and rendering of the EPUB Publication. In the absence of this resource, the Publication might not render as intended by the Author. Examples of Publication Resources include the Package Document, EPUB Content Documents, EPUB Style Sheets, audio, video, images, embedded fonts and scripts.

  With the exception of the Package Document itself, Publication Resources must be listed in the manifest and must be bundled in the EPUB container file unless specified otherwise in Publication Resource Locations.

  Examples of resources that are not Publication Resources include those identified by the Package Document link element and those identified in outbound hyperlinks that resolve outside the EPUB Container (e.g., referenced from an [HTML5] `a` element `href` attribute).

Foreign Resource

  A Publication Resource that is not a Core Media Type. A Foreign Resource requires at least one fallback, as defined in Restrictions and Fallbacks.

Spine

  An ordered list of Publication Resources, typically EPUB Content Documents, representing the default reading order of the Publication.

  Refer to spine for more information.

EPUB Style Sheet (or Style Sheet)

  A CSS Style Sheet conforming to the CSS profile defined in EPUB Style Sheets [ContentDocs30].

Text-to-Speech (TTS)

  The rendering of the textual content of an EPUB Publication as artificial human speech using a synthesized voice.

Unique Identifier

  The Unique Identifier is the primary identifier for an EPUB Publication, as identified by the `unique-identifier` attribute. The Unique Identifier may be shared by one or many Manifestations of the same work that conform to the EPUB standard and embody the same content, where the differences between the Manifestations are limited to those changes that take account of differences between EPUB Reading Systems (and which themselves may require changes in the ISBN).

  The Unique Identifier is less granular than the ISBN. However, significant revision, abridgement, etc. of the content requires a new Unique Identifier.

User

  An individual that consumes an EPUB Publication using an EPUB Reading System.

Viewport

  The region of an EPUB Reading System in which the content of an EPUB Publication is rendered visually to a User.

CSS Viewport

  A Viewport capable of displaying CSS-styled content.

SVG Viewport

  A Viewport capable of displaying SVG images.