A wiki card is content specifically designed to be easily authored and combined with other similarly formatted pages to be viewed as a hypertext.
Federated wiki cards are composed of various kinds of paragraph-like items assembled into a story. One refers to a page by title accepting that there is some ambiguity to be resolved. A history of actions travels with the page to help make sense of duplicates.
The lineup of wiki cards is drawn from multiple sources. Cards are first drawn the immediate source, called the Origin. If the card is not in the immediate source, drawing looks to fallback sources in the Neighborhood.
See Card Source Clues for visual hints as to where cards have been found.
*Footnote*: The term *Wiki Card* may have been called a Wiki Page in content authored prior to late 2018.