Infinity (seembol: ∞) is an abstract concept describin somethin wioot ony leemit an is relevant in a nummer o fields, predominantly mathematics an pheesics. The Inglis wird infinity derives frae Laitin infinitas, which can be translatit as "unboonditness", itself calqued frae the Greek wird apeiros, meanin "endless".
In mathematics, "infinity" is eften treatit as if it wur a nummer (i.e., it coonts or measures things: "an infinite nummer o terms") but it is nae the same sort o nummer as the real nummers. In nummer seestems incorporatin infinitesimals, the reciprocal o an infinitesimal is an infinite nummer, i.e., a nummer greater nor ony real nummer. Georg Cantor formalized mony ideas relatit tae infinity an infinite sets during the late 19t an early 20t centuries. In the theory he developed, thare are infinite sets o different sizes (cried cardinalities). For example, the set o integers is coontably infinite, while the infinite set o real nummers is uncoontable.