OS
What's an OS?
Different Operating Systems
WINDOWS.
Mobile?
✓
iOS.
Mobile?
✓
LINUX.
Mobile?
X
Only Variations.
These are the most popular operating systems.
However, there are others that are rising in popularity, but not exactly on the same level as these three.
Such as:
Ubuntu
SteamOS
Mobile only OS?
The most popular mobile only OS is Android. iOS is also a computer OS, not just a mobile OS.
What's an OS?
Different Operating Systems