A plant is not a purified compound.
Iboga commonly refers to Tabernanthe iboga, a shrub native to Central Africa, and to preparations made from it, often including root bark. Those preparations may contain ibogaine alongside other naturally occurring alkaloids. Ibogaine is a particular indole alkaloid that can be isolated from iboga or made through chemical synthesis.
That distinction is reflected in the basic reference description of Tabernanthe iboga: the botanical source and its cultural history are broader than any one constituent molecule. A whole-plant preparation can vary by plant, part used, processing, storage, and batch. A measured ibogaine product is still not automatically simple or predictable, but its stated material is conceptually narrower.
For a wider orientation to the subject, Cairnflower’s main resource on iboga and ibogaine places this distinction alongside the questions people commonly bring to the topic. The point here is not to collapse one into the other: it is to keep the names attached to the actual material being discussed.