Is mantle l1 or L2?

Could you clarify for me if mantle falls into the category of L1 or L2? I'm trying to understand the classification better, but I'm having some difficulty grasping the nuances. Would you mind explaining it in a way that's easy to grasp? It seems like an important distinction, and I want to make sure I'm not missing anything crucial. Your expertise in this area is highly regarded, so I'm hoping you can shed some light on this matter for me. Thank you in advance for your assistance.