Linux is in widespread use as server system and accounts for a large portion of web servers. However, it is also used in desktop systems and particularly in cell phone software (e.g. Android and some mobile niche OS like Tizen, Maemo, Jolla/Sailfish). Many small, dedicated devices such as DSL routers, NAS, firewalls etc. nowadays run on a specially adapted Linux. Unix paved the way and was the basis for many concepts that we see today in Linux and Unix. By itself it still has a certain relevance, as MacOS is a modified Unix.