Recently Kali Linux 2.0 is released and they release Normal,Minimal and Light ISO installations. Minimal Kali Linux installations has necessary software packages and some other motivations.Some of them are listed here. But what is Light installation? 
Difference between Kali Linux 2.0 mini and Light
kali linux
The mini ISO only provides the minimum necessary to boot Kali and allow installation over the Internet; that's why it's so small. The normal ISO provides the full Kali 2.0 setup using GNOME 3, which now requires 768MB of memory. The light ISO provides a Kali 2.0 setup using XFCE, and a smaller selection of tools (Iceweasel, OpenSSH, NMap, NCrack, SQLMap and AirCrack-NG; see variant-light/package-lists/kali.list.chroot in the live build configuration for details).