Jetpack is the trademarked branded name owned by Verizon to refer to their mobile hotspot devices - regardless of the manufacturer of the device. It is often incorrectly used to refer to any mobile hotspot device on any carrier, much like Kleenex is often used to refer to any brand of facial tissue.
Inseego owns the trademark MiFi for their hotspot devices - so their products for Verizon can be referred by Jetpack, MiFi, or just mobile hotspot device.