Iterative and Incremental Model, need to understand better! Help!

So I need to make a presentation about Iterative and Incremental Model/Process, and I’ve read many references/articles online… but I am still confused about their nature (I guess). There are articles that states the only difference, since both are iterating and incrementing, is how they release deliverables. But then, there are articles that states that incremental model is unidirectional, unlike the iterative model which is cyclical.

I’ve also looked up the definition of the two words, iterative and incremental, iterative means repeating and incremental means adding bit by bits.

How do they really differ??? Since, quoting one of the articles I’ve read, “we cannot build something without iterating to some degree… we cannot release something without incrementing to some degree.”

It’s really confusing me, please help. I’m a student btw, Computer Science.