Device types:
Grouping different devices according to their characteristics into several types.

https://hig.kde.org/introduction/devicetypes.html

These characteristics are

• Input method
• Screen size (in device independent pixels)
• Screen orientation

Device types are used in the HIG to recommend UI/UX patterns for each type.

Devices can change from one type to another, eg rotating screen, adding/removing keyboard and mouse, ...
After some discussion in the kirigami channel it was proposed to have these device types for applications:

• mobile (1 hand use)
  • input method: touch
  • width: < 960 dip in landscape or < 600 dip in portrait
• tablet (convertible in tablet mode) (2 hand use)
  • input method: touch
  • width: >= 960 dip in landscape or >= 600 dip in portrait
• pc (tablet with keyboard+mouse / netbook/laptop / desktop)
  • input method: mouse/keyboard

There might be different devices types to target for workspaces, plasmoids, ... , but that's not the scope of this discussion.

There are several other device types that are out of scope of Kirigami and the KDE HIG for the moment:

• Watches, needing their own design for the tiny screen size
• TV, remote control as input device
• VR Head sets
• ...