The term fan characterises one who has an intense, occasionally overwhelming and often irrational or uncritical admiration or like of a person, group of persons, work of art, idea, or trend. The word "fan" is an Americanism of ca 1889, a shortened version of "fanatic" as an enthusiastic follower of a baseball team.The original "fans" were baseball fans.
"Fanatic" is an invention of ca 1525, meaning "insane person," from modern Latin fanaticus "insanely but divinely inspired" which originally pertained to a temple or sacred place: (fanum, like holy "fane") The modern sense of "extremely zealous," especially in religion, is first attested in the contentious debates of the English Civil War, 1647, where "enthusiasts" and "fanatics" of every stripe had full rein. (The noun is from 1650.)
Collectively, fans may, especially if expressing interest in some organised or consistent manner, coalesce into fandom, be known as a fanbase or start a fan club, particularly when they are fans of music groups. Non-sports fans sometimes self-address as fen.
In a few cases, fans may become so obsessed with the (presumably human) objects of their infatuation that they become stalkers.
The fan (aficionado) should remain distinct from the air-movement device.