“ The quieter you become the more you hear” , this is what Kali Linux promise for it’s offensive Linux user wheras Linux Mint says “ From freedom came elegance.” The basic difference can be listed as:

Kali Linux is not for beginners.

Kali is a Special Purpose Operating System. Its main objective is Pen Testing and Network Security Testing.

Kali has a smaller software repository than Mint, which means not all the software you may use will be available or supported by Kali.

Kali is not a Desktop OS and that is it has no market like Mint( Ubuntu based) which aims for desktops, servers, clouds/clusters and pretty recently phones and tablets.

If you are looking for operating system for network security, penetration testing etc …Mint cannot compete with Kali.

If you want user friendly, general purpose Operating System with the Best GUI,Mint is the Best choice.

Mint is more suited for personal uses while Kali is best for (Ethical) Hackers, vulnerability testers and “nerds” because of the tools they both come bundled with. (Although you can install same set of “Hacking” tools on Mint).

Mint is for beginners who want to learn Linux. It is also used my many people who want their computer to be virus safe. Kali Linux is undoubtedly a penetration tester or an ethical hacker (I won’t talk about Black-Hat-HackerOS.

KaliKali was Backtrack. All the Binary packages meant for Debian could be installed on Kali Linux and from here comes the power of Kali. Moreover the user forum supporting Debian adds strength to KaliKali comes with a number of penetration tools be it Wifi or Database or any other tools, build to be used instantly. Kali uses APT for Package Management.

Mint is a user friendly general desktop/laptop operating system. Kali is a specialized distribution designed for digital forensics and penetration testing.

But if you want to know how the inner system works and wants to be familiar with command line and line, what i suggest is Kali Linux.