For Pentesting, Kali or Ubuntu??

Question

which is the best system to use

Answer 1

Most programs Kali Linux has already installed should be also available in Ubuntu, but you have to install them first. So I'd say if you just want to do pentesting go for Kali and if you want to use the OS also for other things like office, coding etc. go for Ubuntu

Answer 2

Kali is the best, no need to download any tools, allready has a huge repository of tools which can be used without knowing code.