The bar form factor is the most common and simple form factor for a mobile phone. The body of a bar phone is one, single block and has no moving parts (aside from the buttons). “Locking” the keyboard is done to prevent accidental key presses when the phone is carried in a pocket, purse, etc.
Form factor – definition
The general look, or size and shape, of a mobile device.
All mobile phones are similar at the physical style level. Most devices fall into one of the following categories: Bar, Clamshell, Flip down, Slide or Swivel. Mobile manufacturers come up with new designs, but the base they use is normally one of these form factors.
Clamshell – definition
The phone consists of two halves connected with a hinge in the middle. The hinge allows the phone to be folded close (much like a sea clamshell, hence the name). When the phone is closed, the keyboard is protected from accidental key presses.
The top half usually hosts a small external display and a large internal main display, while the bottom half incorporates the keyboard.
The camera (if present) can be on either half.
Flip-down phone – definition
It’s a mobile phone form factor that’s a cross-over between the Bar and Clamshell form factors.
In this case the device is mainly a bar, but a thin “flip” part covers the keypad and/or display when not in use.
