The fourth-generation iPad (marketed as iPad with Retina display, colloquially referred to as the iPad 4) is a tablet computer produced and marketed by Apple Inc. The fourth-generation iPad features new and upgraded components such as the Apple A6X chip, and the Lightning connector, which was introduced on September 12, 2012. It shipped with iOS 6.0, which provides a platform for audio-visual media, including electronic books, periodicals, films, music, computer games, presentations and web content. It was announced at a media conference on October 23, 2012 as the fourth generation of the iPad line, succeeding the third-generation iPad, and was first released on November 2, 2012 in thirty-five countries. The device was released throughout December in ten other countries including China, India and Brazil. The third generation was discontinued following the fourth's announcement. The device is available with either a black or white front glass panel and can be purchased with various connectivity and storage options. Storage size options include 16 GB, 32 GB, 64 GB, and 128 GB; the available connectivity options are Wi-Fi only and Wi-Fi + Cellular with LTE capabilities. The fourth-generation iPad received primarily positive reviews and was praised for its hardware improvements as well as the Retina display, which was also featured in the device's predecessor. Furthermore, benchmarks reveal that the fourth-generation iPad is able to perform CPU-reliant tasks twice as fast as its predecessor. During the first weekend of sales, an aggregated amount of three million fourth-generation iPads and iPad minis were sold. Rumors regarding the next-generation iPad emerged shortly after the release of the third-generation iPad. At that point some speculated that the next iPad released would be of a smaller size.[18] Further speculations emerged in July 2012 when DigiTimes, with the help of unspecified sources, claimed that Apple made small revisions to the then upcoming iPad and scheduled its release for late 2012. On October 16, 2012, Apple announced a media event scheduled for October 23 at the California Theatre in San Jose, California. The company did not pre-disclose the subject of the event, but it was widely expected to be regarding the iPad Mini. Photographic images of the device's dock connector and front camera emerged shortly before the media event. At the media event, Apple CEO Tim Cook introduced a new version of iBooks and new generations of the MacBook Pro, Mac Mini, and the iMac before unveiling the fourth-generation iPad and the iPad Mini. During the unveiling, Apple stated that the fourth-generation iPad would be available to pre-order online in a selected number of countries starting October 26. On November 2, Apple released the Wi-Fi model of device in thirty-five countries across Europe, East Asia and North America. The cellular model was released in-store a few weeks after the initial release of the device. The release of the fourth-generation iPad led to the discontinuation of its predecessor, which angered many third-generation iPad users. In response, Apple extended its 14 day return policy to 30 days. ITProPortal noted that, since the price of both models is identical, consumers that purchased the third-generation iPad within this time frame were effectively allowed to exchange their discontinued device for the fourth-generation model.On January 29, 2013, Apple announced and scheduled the launch of the 128 GB variant of 4th generation iPad. It was released on February 5, 2013. Features [edit] Software [edit] See also: iOS and iOS 6 The fourth-generation iPad is shipped with iOS 6.0. It can act as a hotspot with some carriers, sharing its Internet connection over Wi-Fi, Bluetooth, or USB, and also access the Apple App Store, a digital application distribution platform for iOS. The service allows users to browse and download applications from the iTunes Store that were developed with Xcode and the iOS SDK and were published through Apple. From the App Store, GarageBand, iMovie, iPhoto, and the iWork apps (Pages, Keynote, and Numbers) are available. The iPad comes with several pre-installed applications, including Siri, Safari, Mail, Photos, Video, Music, iTunes, App Store, Maps, Notes, Calendar, Game Center, Photo Booth, and Contacts. Like all iOS devices, the iPad can sync content and other data with a Mac or PC using iTunes, although iOS 5 and later can be managed and backed up without a computer. Although the tablet is not designed to make phone calls over a cellular network, users can use a headset or the built-in speaker and microphone to place phone calls over Wi-Fi or cellular using a VoIP application, such as Skype. The device has a dictation application, using the same voice recognition technology as the iPhone 4S. The user speaks and the iPad types what they say on the screen, though the iPad must have an internet connection available (via Wi-Fi or cellular network) due to the feature's reliance on Apple servers to translate the speech. The fourth-generation iPad has an optional iBooks application, which displays books and other ePub-format content downloaded from the iBookstore. Several major book publishers including Penguin Books, HarperCollins, Simon & Schuster and Macmillan have committed to publishing books for the device. Despite being a direct competitor to both the Amazon Kindle and Barnes & Noble Nook, both Amazon.com and Barnes & Noble offer e-reader apps for the iPad. Hardware [edit] See also: iPad hardware There are four buttons and one switch on the fourth-generation iPad, including a "home" button near the display that returns the user to the home screen, and three plastic switches on the sides: wake/sleep and volume up/down, plus a software-controlled switch whose function varies with software updates. Externally, the fourth-generation iPad is identical to its predecessor apart from the differences between dock connectors used and change of manufacturers that produce the display. In addition, the WiFi only version weighs 652 grams while the cellular model weighs 662 grams – 2 grams heavier than their respective predecessors. The display responds to other sensors: an ambient light sensor to adjust screen brightness and a 3-axis accelerometer to sense orientation and switch between portrait and landscape modes. Unlike the iPhone and iPod Touch's built-in applications, which work in three orientations (portrait, landscape-left and landscape-right), the iPad's built-in applications support screen rotation in all four orientations, including upside-down. Consequently, the device has no intrinsic "native" orientation; only the relative position of the home button changes. The tablet is manufactured either with or without the capability to communicate over a cellular network. All models can connect to a wireless LAN via Wi-Fi. The fourth-generation iPad is available with 16, 32, 64 or 128 GB of internal flash memory, with no expansion option. Apple sells a "camera connection kit" with an SD card reader, but it can only be used to transfer photos and videos. The device has an Apple A6X SoC which comprises an Apple Swift dual-core CPU running at 1.4 GHz, a quad-core PowerVR SGX554MP4 GPU and 1 GB of RAM.[38] It also features a 5-megapixel, rear-facing camera capable of 1080p video recording; and a 720p HD front-facing videophone camera designed for FaceTime. The device features a 9.7" (diagonal) display with a resolution of 2,048 by 1,536 (QXGA) resulting in 3.1 million pixels, this gives the display a pixel density of 264 ppi. The total number of pixels used in the display of the fourth-generation iPad is four times that of the iPad 2 – providing even scaling from the prior model. The audio playback of the fourth-generation iPad has a frequency response of 20 Hz to 20,000 Hz. Without third-party software it can play the following audio formats: HE-AAC, AAC, Protected AAC, MP3, MP3 VBR, Audible formats (2, 3, 4, AEA, AAX, and AAX+), ALAC, AIFF, and WAV. This iPad uses an internal rechargeable lithium-ion polymer (LiPo) battery that can hold a charge of 11,560 mAh. The batteries are made in Taiwan by Simplo Technology (60%) and Dynapack International Technology (40%). The iPad is designed to be charged with a relatively high current of 2 amps using the included 12 W USB power adapter and Lightning connector. While it can be charged by an older USB port from a computer, these are limited to 500 milliamps (0.5 amps). As a result, if the iPad is in use while powered by a computer, it may charge very slowly, or not at all. High-power USB ports found in newer computers and accessories provide full charging capabilities. Apple claims that the battery can provide up to 10 hours of video, audio playback, or web surfing on Wi-Fi, 9 hours of web surfing over a cellular connection, or one month on standby. Like any rechargeable battery, the iPad's battery loses capacity over time. However, the iPad's battery is not user-replaceable. In a program similar to iPod and iPhone battery-replacement programs, Apple promised to replace an iPad that does not hold an electrical charge with a refurbished unit for a fee. During the battery replacement process, user data is not preserved/transferred, and repaired or refurbished units come with a new case. The warranty on the refurbished unit may vary between jurisdictions.