When a phone is no longer just a phone

The basic rule to distinguish between a mobile phone and a mobile computer is to look at how it is utilized. In my view, a device that is used with one hand for over 50% of the time is called a mobile phone. This means that a device which can be operated with one hand while the other hand is carrying shopping bags is considered a mobile phone. The definition of a smartphone adds to this a powerful open operating system and third-party software — usually equipped with a small Qwerty keyboard. All phones must be operable with one hand, but they also allow two-handed operation when necessary — such as when writing emails or watching movies.

If a device requires two hands to operate in most situations, then it does not qualify as a true mobile phone. I define it as a "mobile computer" or "mobile internet device" (MID).