They are fairy tales (=imaginary stories) characters. A fairy can either be helpful and good or mischievious and harmful. A pixie is a mischievous or puckish fairy. They both have magic powers.

A fairy (also fay, fey, faery, faerie; collectively, "fae", wee folk, good folk, people of peace, fair folk, and other euphemisms)[1] is a type of mythological being or legendary creature, a form of spirit, often described as metaphysical, supernatural or preternatural. The word fairy derives from the term fae of medieval Western European (Old French, from Latin fata: Fate) folklore and romance, one famous example being Morgan le Fay ('Morgan of the Fae'). "Fae-ery" was therefore everything that appertains to the "fae", and so the land of "fae", all the "fae". Finally the word replaced its original and one could speak of "a faery or fairy", though the word fey is still used as an adjective or to refer to the word fairy as a plural. Fairies resemble various beings of other mythologies, though even folklore that uses the term fairy offers many definitions. Sometimes the term describes any magical creature, including goblins or gnomes: at other times, the term only describes a specific type of more ethereal creature. Pixies (also Pixy, Pixi, Piskies and Pigsies as they are sometimes known in Cornwall) are mythical creatures of folklore, considered to be particularly concentrated in the areas around Devon [1] and Cornwall, [2] suggesting some Celtic origin for the belief and name. They are usually depicted with pointed ears, and often wearing a green outfit and pointed hat. Sometimes their eyes are described as being pointed upwards at the temple ends. These, however, are Victorian Era conventions and not part of the older mythology. cowboy...

Hello Sonia, Fairies are tiny imaginary supernatural creatures. Little fairies are commonly tiny human like creatures ( usually females) with wings. Pixies are a type of mischievous fairies ( fairy like creatures) who can take on many forms and enjoy stealing horses to ride .Pixies are usually wingless with pointed ears and often wear a pointed hat and green clothes.