The different releases offer different default selections of packages, using metapackages. I’ll list the differences below; look up the referenced metapackages in the previous link to get the full details.
The “standard” (GNOME) Kali setup includes:
- the live desktop;
- the core Linux tools (
kali-linux-core
): tools to access remote file systems (NFS, Samba, etc.), partition management, archivers, wireless access, OpenVPN, the OpenSSH server, Vim, ...
- the GNOME desktop;
- the default Kali selection (
kali-linux-default
): most of the analysis tools you’d expect in a standard Kali installation.
The light variant includes:
- the live desktop;
- the core Linux tools (
kali-linux-core
, indirectly);
- the Xfce desktop;
- a light selection (
kali-linux-light
) — this pulls in the core tools, and only adds Firefox.
The large variant includes everything in the standard setup, and adds a lot of additional tools (kali-linux-large
).
Put another way, the light setup provides the live desktop with Xfce, Firefox, and the core tools needed to access the network and data stored there. The standard setup replaces Xfce with GNOME, and adds all the analysis tools Kali became famous for. The large setup adds even more such tools (corresponding to the default selection in the past).