You probably know only Windows and now you want to use Linux because you read that Linux is better than Windows as it is more secure and you don’t have to buy a license to use Linux.

But then when you go about downloading and installing Linux, you learn that Linux is not a single entity. There are Ubuntu, Fedora, Linux Mint, elementary and hundreds of such ‘Linux variants’. The trouble is that some of them look just like the other.

If that’s the case, why there are multiple of those Linux operating systems? And then you also learn someone mentioning that Linux is just a kernel not an operating system.

https://itsfoss.com/what-is-linux/