KMZ is KML packed into a ZIP archive. Content is identical, but KMZ is more compact and can include icons, textures, and other resources.
| Criteria | KMZ | KML |
|---|---|---|
| File size | Compact | Large |
| Embedded resources | ✓ | ✗ |
| Text editing | ✗ | ✓ |
| Google Earth | ✓ | ✓ |
| Email sharing | ✓ | ✗ |
For sharing, compact storage, files with icons/textures.
For manual XML editing, debugging, code integration.