• It’s very well-known and common knowledge. It’s certainly something that I will talk about without feeling the need to define terms or something. I would assume anyone unfamiliar with it either didn’t pay attention in school or never went to school to begin with.

      • It’s never too late to learn about them. They’re super common in practice so it’s very helpful to know about them. A lot of things are a DAG, like tree data structures and dependency graphs. Having no cycles in a directed graph has a lot of nice properties too, like allowing one to use efficient graph traversal algorithms, topological sorting, or its transitive closure. It’s come up multiple times in my career so it’s definitely worth knowing imo.