Ubuntu is a Linux(Server) Distribution. It is for FREE open source and much more secure then windows. There is a big ubuntu community on the internet so you can ask your questions if you got troubles. the biggest tech companies like google,facebook, yahoo .... also uses Linux Distros for there services.
https://www.zdnet.com/article/google-moves-to-debian-for-in-house-linux-desktop/
So feel free and dont hesitate to try open source.
;=)