I touched centOS in the business of the company. ... but I have no idea what it was for, what it was used for, or what it could do. I didn't know the purpose and put centos in AWS according to the manual (maybe I made a mistake), and I was sick. But I don't know what I'm doing at all, so I'll look it up and write an article.
https://eng-entrance.com/what-is-centos Refer to the above article. centOS seems to be a clone of the paid version of Linux. I've heard of Linux. It's the one who drives something into the black screen. But it seems that it was released for free ...?
https://www.lifehacker.jp/2017/11/171105-how-to-get-started-with-the-linux-operating-system.html After reading this article, it is clearly stated that Linux is also provided free of charge. However, it seems that there are various types of Linux in a bite, and various types are called distributions. centOS seems to be one of the distributions in Linux.
It's even more complicated, but when I read the first article, Red Hat Enterprise Linux (paid) → clone → centOS (free) It seems to be an image It's probably for those who want to use Red Hat Enterprise Linux easily (?).