Raspberry Pi OS, also called by it's former name of 'Raspian', is a Linux distribution descending from Debian that is pre-installed on all models of the Raspberry Pi computer. The desktop variant targets the general computing market. The desktop has pre-installed office, development, and education software. It uses the lightweight PIXEL desktop, derived from LXDE, at the expense of an older design. A 'lite' version is also available that uses a CLI. Raspberry Pi OS brings the basics to the basic Raspberry Pi computer and works for many computing needs (web browsing being a good example).