Before the emergence of 2-in-1s and their denomination as such, technology journalists used the words convertible and hybrid to denominate pre-2-in-1 portable computers: Convertible typically denominated those that featured a mechanism to conceal the physical keyboard by sliding or rotating it behind the chassis, and hybrid those that featured a hot-pluggable, complementary, physical keyboard. Both pre-2-in-1 convertibles and hybrids were crossover devices that combined features of both tablets and laptops. The later 2-in-1 PCs comprise a category that is a sibling to both the pre-2-in-1 convertibles and hybrids. Models of 2-in-1 PC were each similarly denominated either a 2-in-1 convertible or 2-in-1 detachable, respectively, and despite borrowing the terminology of the pre-2-in-1 PCs, the two species of 2-in-1 PCs are distinct from the two species of pre-2-in-1 PCs because 2-in-1 PCs have additional features of traditional laptops.
2-in-1 PCs consist of portable computer components within light and thin chassis, and exemplify technological convergence. They are convenient for media consumption and non-intensive tasks in tablet mode yet useful for content production in laptop mode.
2-in-1 convertibles are tablets with the ability to rotate, fold, or slide the keyboard behind the display. On most devices, the hinge is situated at the display and keyboard junction. However, the Dell XPS Duo is unique in that the display sits in a frame that allows the screen to be spun.
2-in-1 detachables are devices with detachable keyboards. In most cases, the keyboard part provides few, if any, additional features (most often a touchpad, as in the HP Spectre x2). However, the keyboards of some detachables provide additional features similar to those of a docking station such as additional I/O-ports and supplementary batteries. For instance, the Surface Book can leverage the discrete GPU in the keyboard upon the keyboard's connection.
When connected to the keyboard, the display of the detachable can either be free-standing on the hinge or require external support, often in the form of a kickstand. Novel ways of providing external support include the bending frame and locking mechanism of the HP Spectre x2.
Though the keyboard is usually bundled with the purchase of a 2-in-1 detachable, it is occasionally deemed an optional accessory by manufacturers in order to minimize the starting price of a device. In such cases the 2-in-1 detachable is often displayed with its complementary keyboard in advertisements and promotional materials. This is true for all devices of the Surface and Surface Pro lines.
2-in-1s fall in the category of hybrid or convertible tablets but are distinct in that they run a full-featured desktop operating system and have I/O ports typically found on laptops, such as USB and DisplayPort. The most prominent element is the keyboard that allows the 2-in-1 to provide the ergonomic typing experience of a laptop.
While 2-in-1s fall in a category distinct from laptops, they loosely parallel the traits of the Ultrabook device category, having light and thin chassis, power-efficient CPUs, and long battery lives. They are distinguished from traditional Ultrabooks by the inclusion of a touchscreen display and a concealable or detachable keyboard.
The earliest device that can be considered a 2-in-1 detachable is the Compaq Concerto from 1993. It came preinstalled with Windows 3.1 and Windows for PEN, and had a cabled detachable keyboard, and battery powered stylus.
Mainstream attention for 2-in-1 PCs was not achieved until nearly two decades later, when Asus launched the Asus Eee Pad Transformer TF101 in 2011. It was the first of its Transformer series, mainly running the Android operating system.
Microsoft started its own line of 2-in-1s with the introduction of the Surface Pro series, the first of which was released in February 2013. It had a 10.6-inch (27 cm) display, Intel Core i5 CPU, and included the Pro Pen stylus and a detachable keyboard that doubled as a protective screen cover. In 2015 Microsoft introduced the Surface Book series, which, similar to the Surface Pro series, features a detachable keyboard cover and Surface Pen stylus.
Samsung entered the 2-in-1 PC market with the release of the Samsung Galaxy TabPro S, which was released in March 2016. It had a 12-inch display, Intel Core m3 CPU, a first-party keyboard attachment, and a TabPro Pen. In February 2017 Samsung also released the Galaxy Book, which came in a 10.6-inch model and a 12-inch model; both models have an improved detachable keyboard and include an S Pen.
Since 2012, a number of other prominent laptop manufacturers, such as Lenovo, Dell, Acer, HP, and Sony have also begun releasing their own 2-in-1s. While the Apple iPad has an optional keyboard accessory, Apple has yet to release a true 2-in-1 PC with a full desktop OS, citing the quote below.
In April 2012 Apple's CEO Tim Cook, answering to the question of the researcher Anthony Sacconaghi about a possible hybrid of iPad and MacBook, compared a 2-in-1 to a combination of "a toaster and a refrigerator" that "doesn’t please anyone":
|“||I think, Tony, anything can be forced to converge. But the problem is that products are about trade-offs, and you begin to make trade-offs to the point where what you have left at the end of the day doesn’t please anyone. You can converge a toaster and a refrigerator, but those things are probably not going to be pleasing to the user … you wouldn’t want to put these things together because you wind up compromising in both and not pleasing either user. Some people will prefer to own both, and that’s great, too. But I think to make the compromises of convergence, so — we’re not going to that party. Others might. Others might from a defensive point of view, particularly. But we’re going to play in both.||”|
|— Tim Cook, Apple's CEO|
2-in-1s are natively supported by the Windows 8, 8.1 and 10, and Chrome OS operating systems. Various other Linux distributions also support some touch features of 2-in-1s, though they are generally unsupported by hardware vendors.