KMZ

KMZ is a format closely related to KML which in practice is KML within a ZIP file. KMZ files are, in fact, ZIP files, and the benefit of KMZ is compression and the ability to store other files in the package.

Placemark supports importing & exporting KMZ files, but it should be noted that any additional files in imported KMZ files will be ignored.

References

• KMZ on Google's Reference Site