Digimon are fictional creatures from the Japanese Digimon media franchise. They are central to several anime series and films, manga, video games and other merchandise. The word "Digimon" is invariable in the plural, and stands for "Digital Monster". Digimon include almost all the creatures that reside within the fictional parallel universe called the "Digital World." There are currently 881 different species of Digimon, as well as unconfirmed and new generations of Digimon yet to be revealed. The rate of new Digimon species continuously increase as the Digital World expands each year.