sys­temd

Sys­temd is a sys­tem and ser­vice man­ager for Linux oper­at­ing sys­tems. One of the main func­tions of sys­temd is to man­age the ser­vices, devices, mount points, sock­ets and other enti­ties in a Linux sys­tem. Each of these enti­ties that are man­aged by sys­temd is called a unit. Sys­temd has replaced the init dae­mon in most Linux dis­tri­b­u­tions to start the var­i­ous units on sys­tem boot.