This link from Dmitri Ponomareff provides a great introduction to Scrumban, the hybrid approach blending Scrum and Kanban. In fact, it stands as a very high-level digest of both of those practices as well. While Kanban and Scrum have a formal structure to them, Scrumban doesn't - and this is a key point of Dmitri's piece.
Scrum as framework is explicit in terms of its events, artifacts like the backlog, and roles - take one thing away from these "guardrails" and you fall into Scrumbut. As in "we do Scrum, but... "we skip retro's", or "we don't do stand-up every day". However, Scrum allows for additions that supplement and strengthen it - e.g. User Stories, Pair Programming, etc. (Side note: nothing in the Scrum Guide references User Stories - yet can you imagine Scrum without them?). So applying Kanban's Work In Progress limits can easily be folded into Scrum.
Kanban is arguably less formulaic than Scrum. Kanban's focus on making policies explicit and visualizing work make Scrum concepts easily included into Kanban. And as Kanban implementation kicks off with "start with what you do now", Scrum can serve as a great starting point.
As the article points out, both practices are aligned strongly with the Agile principles and values. Both also have a sharp focus on continuous improvement - which to me suggests seeing where the two practices can borrow from or be influenced by one another.