Ubuntu Server is Ubuntu specially developed for server operating systems. There is definitely a difference between Ubuntu and Ubuntu Server. On Ubuntu Server is not provided Graphical User Interface (GUI). This means that all forms of program execution are run through the command line called the Command Line Interface (CLI). For users who are always afraid of computers having security problems or malware that usually attacks Windows, this Ubuntu server is the right system because it is claimed to be more secure than the Windows operating system.
Ubuntu 20.04 Focal Fosa is the latest LTS version of Canonical's system and will be supported until April 2025. Until then, Canonical will release at least three more dot updates. Codenamed Focal Fossa from a cat-like creature from Madagascar. This is a Long Term Support (LTS) release, which means it will come with software patches and security fixes for the next 5 years.