Waterfall and Scrumban take two different approaches to project management so there are a lot of difference between the two.
The first difference being is that Scrumban is a lot more flexible allowing you to go through the project as you choose whereas Waterfall is much more structured where you’re not able to move onto the next phase of the project until the previous phase has been completed. Another difference seen between the two is that Waterfall projects require you to define your requirements in advance whereas with Scrumban requirements are expected to and can be changed throughout the course of the project. Lastly in Waterfall you can’t change things that were done in previous stages and in Scrumban you are able to do so. Since the two programs are essentially designed to be opposites of each other there are not a whole lot of similarities other than that they are both project management programs.