Is DAG layer 1?

Could you clarify for me if the Directed Acyclic Graph (DAG) technology commonly associated with some blockchain projects should be considered as a Layer 1 solution? I'm interested in understanding if DAGs are positioned at the foundational layer of the blockchain architecture, similar to how traditional blockchain networks operate as Layer 1, or if they serve a different purpose and operate on a different layer entirely. Your insights would be greatly appreciated.