Is saga a genre?

Excuse me, I'm curious about the classification of literature. I've come across the term 'saga' and I'm wondering, is saga a genre in and of itself, or is it more of a descriptive term that can apply to various types of narratives? If it is indeed a genre, what are some of the defining characteristics that set it apart from others? And if not, could you elaborate on how it's commonly used and the types of stories it typically encompasses?