A sub property of description. A short description of the item used to disambiguate from other, similar items. Information from other properties (in particular, name) may be necessary for the description to be useful for disambiguation.

A description of the item.

The name of the item.

Permission(s) required to run the app (for example, a mobile app may require full internet access or may run only on wifi).

The date on which the CreativeWork was created or the item was added to a DataFeed.

Date the content expires and is no longer useful or available. For example a [VideoObject](https://schema.org/VideoObject) or [NewsArticle](https://schema.org/NewsArticle) whose availability or relevance is time-limited, a [ClaimReview](https://schema.org/ClaimReview) fact check whose publisher wants to indicate that it may no longer be relevant (or helpful to highlight) after some date, or a [Certification](https://schema.org/Certification) the validity has expired.

Media type typically expressed using a MIME format (see [IANA site](http://www.iana.org/assignments/media-types/media-types.xhtml) and [MDN reference](https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/MIME_types)), e.g. application/zip for a SoftwareApplication binary, audio/mpeg for .mp3 etc. In cases where a [CreativeWork](https://schema.org/CreativeWork) has several media type representations, [encoding](https://schema.org/encoding) can be used to indicate each [MediaObject](https://schema.org/MediaObject) alongside particular [encodingFormat](https://schema.org/encodingFormat) information. Unregistered or niche encoding and file formats can be indicated instead via the most appropriate URL, e.g. defining Web page or a Wikipedia/Wikidata entry.

Actual bytes of the media object, for example the image file or video file.

An additional type for the item, typically used for adding more specific types from external vocabularies in microdata syntax. This is a relationship between something and a class that the thing is in. Typically the value is a URI-identified RDF class, and in this case corresponds to the use of rdf:type in RDF. Text values can be used sparingly, for cases where useful information can be added without their being an appropriate schema to reference. In the case of text values, the class label should follow the schema.org [style guide](https://schema.org/docs/styleguide.html).

Indicates an item or CreativeWork that this item, or CreativeWork (in some sense), is part of.

The identifier property represents any kind of identifier for any kind of [Thing](https://schema.org/Thing), such as ISBNs, GTIN codes, UUIDs etc. Schema.org provides dedicated properties for representing many of these, either as textual strings or as URL (URI) links. See [background notes](https://schema.org/docs/datamodel.html#identifierBg) for more details.