A tablet computer (sometimes shortened to "tablet") is a self-contained mobile computer with a touch-sensitive screen. A variety of tablet computers have been created over time, but most agree that Apple Inc. shaped the tablet market in 2010, when they released their iPad. Most modern tablets include basic computer components, a battery, a microphone and speaker, angle sensor, accelerometer, and camera.
The slate is what most people think of as a tablet computer. It is lightweight, thin device. These usually offer all the features usually associated with tablet computers. Slate tablets are designed to be functional without any other hardware, so a touchscreen and an on screen keyboard are expected of such modern devices. Many also have handwriting recognition, so users can enter text using only a finger or stylus. Slates also usually have the ability to connect to projectors, computer monitors, and keyboards. This enables easy sharing or usage as both a tablet and desktop computer.
Mini tablets are a newer development in the tablet computer market, which are sized similarly to books. Often sized at seven to eight inches diagonally, these are designed to be more convenient for spontaneous use, when it may not be practical or possible to keep a slate available. These tablets are also often less expensive than slates, so casual users will sometimes select these to save money.
A "Phablet" (portmanteau of Phone tablet) is a type of tablet computer/smartphone which is even smaller than a mini tablet, and can be used as a cellular phone. These devices usually measure diagonally at between five and seven inches. At first, these were little more than smartphones in size, but they have been enlarging over time. These are designed to be small enough that they can be carried around like a smartphone, but large enough that they can offer a better screen and therefore more functionality.
Rugged tablets are designed for workplaces and other situations where electronics might be put at risk. These tablets are built in a sturdy frame, with shock-absorbing cases and internal mounts. These tablet computers still offer great versatility, depending on the kind chosen. They are often used in construction areas, site surveys, and mail delivery, where they could be dropped or struck at any time as work progresses.
Gaming tablets are as the name suggests, intended for playing games. They usually have advanced graphics cards, and often include attached physical gaming controls and external game controller support. These are usually sized as slate tablets.
Booklet tablets are as the name states, in the form of a booklet. They offer two touchscreen panels, which fold together when not in use. This offers more screen space but also better protection for the screens, all without increasing the width of these devices, making them harder to transport.
Hybrid ("convertible") tablets are devices which can be used as either laptops or tablets. Some employ detachable designs which enable the user to simply take off he screen and use it separately, while others offer a convertible design, which enables users to swivel the laptop's screen around and fold it down, so that the entire device becomes a sort of tablet. Some contest that these "hybrid" devices are always either tablets with attached keyboards (as with the detachable design), or laptops with special screen hinges (as with the convertible design). Regardless of how people choose to look at these devices, they have become popular.
There is some confusion as to whether E-readers qualify as tablets. Most people agree that modern e-readers do qualify, but some models do not offer basic functions expected of modern tablets. While Amazon's Kindle Fire certainly counts, Aluratek's Lebre is designed for little more than reading books and playing media. The Lebre does not as of 2016 offer a touchscreen, camera, or other sensors, but since the term "tablet" is loosely defined, most count it anyway.
Tablets need some kind of system to operate hardware and support software. There are a variety of systems which can do this effectively.
Apple's iOS is one common system, which in included with all iPad tablets. This is a fairly secure system which most find easy to use.
Another common system which is especially used on cheaper tablets is Google's Android system. This system is also fairly secure from attackers, although some dislike it due to the privacy concerns that come with its constant communication with Google. This system does generally offer more customization options than others on the market.
Windows has for some time offered mobile systems which are used on smartphones and tablets. These were previously designed separately from desktop systems, and although slightly different than their counterparts, still fairly popular. However, when Windows 8 was released, it was designed to work on tablets and smartphones as well as desktop and laptop computers. The system did not do as well as expected for desktops, but some found it convenient to have the same system on all their devices, so Microsoft has continued with this concept.
Mozilla is also joining this list, as they are developing their own mobile system. As of 2016, this system was not available to the public, but release was expected in the near future. This system is intended to be for mid-range devices.
Research in Motion has also released and continued to develop a system for its BlackBerry PlayBook. It is a fairly secure and versatile system, although it has not become incredibly popular. However, contrary to rumor, the PlayBook is still being produced and sold, and is turning a profit.
There are also Linux systems available for tablets. These include Maemo (rebranded MeeGo in 2010), Ubuntu, Tizen (developed by Intel and Nokia), and Fedora, among many others. Each system offers different features, but they are generally secure and stable systems.
Hewlett Packard released the last version of WebOS (3.0) on their TouchPad in June 2011. On August 18, 2011, HP discontinued the TouchPad, due to poor sales. After WebOS going unused for over a year, HP announced they were selling WebOS to LG Electronics in February 2013. It has not been released since then as a standalone system, but has been used instead as a part of LG's Smart TV system.