The antagonistic Androids are most commonly associated with Dragon Ball Z, but their origins go all the way back to the original Dragon Ball. Androids 17 and 18, as well as Cell, are essential characters in the sequel series, but Android warriors were first introduced in the Red Ribbon Army saga. Androids disappeared for a lengthy hiatus following the original series and were pretty much forgotten until their apocalyptic return in Dragon Ball Z.
Source：https://www.cbr.com/dragon-ball-androids-ranked/
