2-in-1 most often refers to a laptop computer with a touch screen that has a removable keyboard and is designed to support an onscreen keyboard as a replacement. For another kind of 2-in-1 see PadFone X mini. It can also refer to the Bluetooth KN321 RX, TX.
This idea of an 2-in-1 laptop is to provide both a laptop and a tablet in a single device. It is advertised as replacing a normal laptop and as such it will typically (but not always) run a Windows 8 Operating System. As a laptop they would generally fall into the category of Sub-notebooks due to their small size and light weight. They are usually one step up from a Web Tablet. The Surface Pro 3 is a tablet that offers a keyboard option that may be attached to turn it into a 2-in-1. They differ from a Tablet PC in that the keyboard is fully removable, thereby reducing the weight when only a tablet is needed. Often the keyboard contains additional features like USB host ports and may weigh nearly as much as the screen (tablet) half.
Essential in the design of the software is the need to replace both the keyboard and the mouse as neither are available on a tablet. In addition the tablet mode is expected to be able to run traditional PC applications that were never originally designed for tablet use. The touch screen using the human finger is a poor substitute for the precise nature of the mouse which means that a stylus such as the one available from wacom is sometimes employed. In other cases the user must resort to zooming the screen in order to tap a menu items.
 Design features
The screen (tablet) module contains all of the computer hardware and will typically include a slave USB port which may also be the charging connector. This would allow it to behave as a regular tablet when hooked to another computer. It will also often contain an expansion micro-SD card slot.
A 2-in-1 uses a solid-state disk drive (Flash ROM) to lower power requirements and provide a lightweight Tablet use. The battery life rivals the life of regular tablets and is typically much more that a laptop.
Some units offer add-on disk drives and even CD/DVD drives as an option. These are contained in the keyboard module. The keyboard module may also contain a second battery to extend battery life of the unit. Of course the inclusion of a USB master port in the keyboard module facilitates external devices as well but this would restrict the portability.
 Available Devices
- Asus Transformer T100TA - Runs Windows 8
- Asus Transformer TF103C - Runs Android 4.4
- Asus Transformer T200TA - Runs Windows 8, Keyboard can hold a disk drive.
- Toshiba Click 2 13.3" screen
- Toshiba Click 2 Pro Higher powered model, can have a hard disk in the keyboard.
- Surface Pro 3 and Surface Pro 4 from Microsoft is a tablet with an option cover/keyboard
- Lenovo Yoga laptop series - This is really a Tablet PC but advertised as a 2-in-1
- Surface Book is a full 2-in-1 with a 13.5" screen, a touchscreen laptop. It could also be classified as a Tablet PC
- Notion Ink Cain Black a 10.1" has the keyboard cover and built in stand; includes a pen.
- HP Elite x2 has a 12.0" screen with travel keyboard, several models.
- Google pixelbook a chromebook 2-in-1 that runs Android apps locally.
- Acer R11 11.6" runs Chrome OS with Android support