MIDs these days have tablet form factors that generally include touch-sensitive screens in the 7-inch (17.8-centimeter) to 10-inch (25.4-centimeter) diagonal size range, allow you to get on the net via cellular or WiFi and surf to your heart's content, let you install and run various applications (almost universally referred to as "apps") and include a wide variety of other options that run the gamut. They all have small, lower-powered and relatively inexpensive versions of the components found in larger computers, including central processing units (CPUs) to handle most computing tasks, graphics processing units (GPUs) to allow for rendering of images, an input device that is most often a capacitive touchscreen (rather than the mouse or keyboard of yore) and some method of connectivity, which for wireless devices can include WiFi, cellular or Bluetooth.
Their microprocessors and other internal components were designed specifically for mobile devices. The core processing components (the aforementioned CPU and GPU, and additional items that interface with peripherals) are most often included in one tiny package as a system on a chip (SoC) rather than being installed as separate items. There are different mobile device processor architectures, including those developed and licensed out by the companies ARM and MIPS, and that of Intel's Atom chip line based on its x86 architecture. ARM was early to create chip designs optimized for the needs of small mobile devices, and they have since dominated the market. ARM-based processors and SoCs are present in the vast majority of mobile devices, including the iPhone and iPad. Intel and MIPs are having a hard time catching up, but they have come up with similarly impressive architectures that meet the needs of mobile devices.
These SoCs are optimized to have a good trade off between things like performance and battery life, with enough speed and processing power to allow your device to run games, play high-definition videos and browse the Internet without taking up too much space, draining the battery too quickly or generating a lot of heat. This allows manufacturers to pack a lot of processing ability into a very small device, enabling them to forgo things like cooling fans which would make the devices too large.
With the help of these small but powerful components, MIDs' speeds vary from 600 GHz to 1.5 GHz, on average. Most have 512MB to 1GB of random access memory (RAM), with a few on the fringes with as little as 256MB and as much as 2GB. Most come with anywhere from 2GB to 64GB of built-in flash memory for application and data storage space, and many have SD card slots and USB ports that allow you to plug in cards or drives that expand the available storage.
Screen resolutions mostly range from 800 by 480 pixels to 1240 by 768, with lots of variation in resolution and aspect ratio in between. Some of the cheapest ones rely on resistive touchscreen technology, which requires an amount of pressure be put on the screen and does not allow for the multi-finger screen manipulation that many of us are used to today (it does, however, allow for the use of a stylus). But even many of the cheaper ones now have the better and more responsive capacitive multi-touch touchscreens that allow you to simply slide your fingers across the screen, and enable you to do things like use two fingers to zoom in or out of a Web site or image. The less expensive MIDs are also often running the older model single-core ARM processors, with their more expensive compatriots running newer, faster and more powerful dual and quad-core models that are better at multitasking.
MIDs include an array of potential connectors, including HDMI, HDMI-mini, full-sized USB, micro and mini-USB, microphone and headphone jacks and various sizes of SD card slots, among others. These can be used to plug in storage devices and other peripherals including Bluetooth dongles (if the tablet doesn't already come with Bluetooth), additional USB hubs, keyboards, mice and the like. If there is an HDMI port, you can use an adapter to connect the device to your television or other HDMI monitor and use the larger screen for output. Some of these connectors also come in handy for loading data to the device that you can't just download from the Web. Some have tiny built-in speakers. At least one even has a keyboard docking station that both powers the device and converts it into something resembling a laptop, if that's what you need. The devices also have various sensors like accelerometers and gyroscopes that allow you to use the motion of the device itself as an input (say, tilting the MID one way or the other to move through a game).
All of them, even the economy models, contain impressive hardware. Read on to find out about more about their software, especially the most common MID operating systems.