From Wikipedia: Ubuntu is a Linux distribution based on Debian and mostly composed of free and open-source software. Ubuntu is officially released in three editions: Desktop, Server, and Core for Internet of things devices and robots. All the editions can run on the computer alone, or in a virtual machine. Ubuntu is a popular operating system for cloud computing, with support for OpenStack. Ubuntu's default desktop has been GNOME, since version 17.10.
Ubuntu is released every six months, with long-term support (LTS) releases every two years.
Downloading Ubuntu Install files
Ubuntu is open-source software. Installation files can be downloaded from https://ubuntu.com/#download.