Normal maps are texture files that add surface detail to 3D models, while Unity 3D models are 3D assets optimized for the Unity game engine.
Normal maps use color data to simulate small surface features (like bumps or scratches) without extra geometry, keeping models lightweight. Unity 3D models are meshes, textures, or animations formatted (e.g., FBX) to work with Unity’s tools for games or interactive apps.
Applying normal maps to Unity 3D models is a common way to boost visual realism in Unity without increasing performance costs.