What is kali linux? what is its purpose? Why should i install it on a VM?

I almost want to explore every field which i studied during my educational career, My first priority was development, now as i have a sound knowledge of development so now i want to explore the Network security field, Cyber attacks, threats, malwares, phishing, social engineering. I read about these topics in my University, but now i want to learn how actually its get done, someone recommended me to explore Kali linux, as its widely used for these purposes, Is it? If it is, then i want to learn its tools, and i need guidance how do i start? Any help will be appreciated. I'd love the hear the pros and cons of Kali linux.