Iterative and incremental are not separate development approaches on their own but are practices or characteristics that can be part of the predictive, hybrid, or adaptive approaches.
A predictive (waterfall) approach may follow an incremental strategy when delivering parts of a project sequentially, when the scope is clearly defined and the team has done this type of work before.
An adaptive approach (agile) often combines both iterative and incremental practices to refine and deliver a product in increments over multiple iterations, when scope is not clearly defined or requirements change frequently.
Hope this helps!
