When saving FBX 3D models as an artist, export from your 3D software (e.g., Blender, Maya): select the model, open the export menu, choose FBX format, and adjust compatibility settings (like embedding textures or preserving animation).
FBX is a universal interchange format—exporting (not just saving) retains key data (normals, UVs, rigs) so your model works in other tools (game engines, renderers).
Always test the exported FBX in your target app (e.g., Unity) to fix issues like missing textures or broken geometry early.