The main difference between 2D image 3D models and manual modeling 3D models is their creation process: 2D image models are generated by software from 2D photos/scans (via photogrammetry or AI), while manual models are built step-by-step by designers using 3D tools.
2D image-based modeling is fast for replicating real objects but has less customization, as it relies on existing 2D data. Manual modeling lets designers control every detail (shapes, textures, proportions) for original or precise designs but takes more time and skill.
If you need a quick 3D copy of a real item (like a product or landmark), use 2D image tools (e.g., Meshroom). For unique designs (e.g., game characters, furniture), try manual tools like Blender—both are free to start with.