Semantic wikis, on the other hand, provide the ability to capture or identify information about the data within pages, and the relationships between pages, in ways that can be queried or exported like a database[1][2] through semantic queries.
The page for an apple would contain, in addition to standard text information, some machine-readable or at least machine-intuitable semantic data.
In the 1980s, before the Web began, there were several technologies to process typed links between collectively maintained hypertext pages, such as NoteCards, KMS, and gIBIS.
Extensive research was published on these tools by the collaboration software, computer-mediated communication, hypertext, and computer supported cooperative work communities.
The first known usage of the term "Semantic Wiki" was a Usenet posting by Andy Dingley in January 2001.
Freebase, though not billed as a wiki engine, was a web database with semantic-wiki-like properties.
Users may be supported when adding this content, using forms or autocompletion, or more complex proposal generation or consistency checks.
Separate versioning support or correction editing for the formalized content may also be provided.
One may be able to specify types for pages, categories, or paragraphs or sentences (the latter features were more common in pre-web systems).
More reflexive user interfaces provide strong ontology support from within the wiki, and allow it to be loaded, saved, created, and changed.
Many semantic wikis can display the relationships between pages, or other data such as dates, geographical coordinates, and number values, in various formats, such as graphs, tables, charts, calendars, and maps.