Ipad

The iPad is a tablet computer designed and marketed by Apple for Internet browsing, media consumption, gaming, and light content creation. Released in April 2010, it established a new class of devices between smartphones and laptops.

              Similar to the older (and smaller) iPod Touch and iPhone, the iPad runs a modified version of the iPhone OS and is controlled by a multi-touch LCD sensitive to fingertips, instead of a stylus as with earlier tablet computers.  It runs iPad-specific applications as well as those written for the iPhone and iPod Touch, including e-book readers.
          The iPad uses Wi-Fi or a 3G data connection to browse the Internet, load and stream media, and install software.  A USB cable is required to sync the iPad with iTunes on a personal computer.

   SOFTWARE

              Like the iPhone, with which it shares a development environment (iPhone SDK, or software development kit, version 3.2 onwards),  the iPad only runs its own software, software downloaded from Apple's App Store, and software written by developers who have paid for a developer's license on registered devices.  The iPad runs almost all third-party iPhone applications, displaying them at iPhone size or enlarging them to fill the iPad's screen.  Developers may also create or modify apps to take advantage of the iPad's features. Application developers use iPhone SDK for developing applications for iPad.

  AUDIO AND OUTPUT

           Dual speakers housed inside the iPad provide mono sound via two small sealed channels in the interior speaker assembly that direct the sound outwards toward the three audio ports carved into the bottom-right of the unit. The microphone is within the device. A volume switch is on the right side of the unit, and a 3.5 mm TRS connector audio-out jack provides stereo sound for headphones on the top-left corner of the device. The iPad supports normal headphones and models with microphones, volume controls, or both. Microphones can be used for voice recording.

The built-in Bluetooth 2.1 + EDR interface supports the HSP, A2DP, and HID profiles, which allow wireless headphones and keyboards to be used with the iPad. However, the iPhone OS does not currently support the OBEX file transfer protocol.

iPad video output over VGA is set to 1024 x 768 using a 720p scan rate.

   SCREEN AND INPUT

The touchscreen is a 25 cm (9.7 in) liquid crystal display (1024 × 768 pixels, 132 ppi, XGA) with fingerprint–resistant and scratch-resistant glass. Like the iPhone, the iPad is designed to be controlled by bare fingers; normal gloves and styli that prevent electrical conductivity may not be used  although there are special gloves and styli designed for this use.
The display responds to two other sensors: an ambient light sensor to adjust screen brightness and a 3-axis accelerometer to sense iPad orientation and switch between portrait and landscape modes. Unlike the iPhone and iPod touch built-in applications, which work in three orientations (portrait, landscape-left and landscape-right), the iPad built-in applications support screen rotation in all four orientations (the three aforementioned ones along with upside-down), ^] meaning that the device has no intrinsic "native" orientation; only the position of the home button changes. Most third-party iPad applications also support these four orientations.
The iPad has a switch to lock out this screen rotation function (reportedly to prevent unintended rotation when the user is lying down).  There are a total of four physical switches, including a home button below the display that returns the user to the main menu, and three plastic physical switches on the along with the screen rotation lock.

   CONNECTIVITY

The iPad can use Wi-Fi network trilateration from Skyhook Wireless to provide location information to applications such as Google Maps.  The 3G model contains A-GPS while both models have a digital compass.
The back of the Wi-Fi model iPad is made of contoured aluminum with black plastic buttons. The Wi-Fi + 3G model also has a black plastic accent on top of the device which helps with 3G radio sensitivity.

   POWER AND BATTERY

The iPad uses an internal rechargeable lithium-ion polymer battery. The batteries are made in Taiwan by Simplo Technology, which makes 60% of them, and Dynapack International Technology.  The iPad is designed to be charged with a high current (2 amperes) using the included USB 10 W power adapter. While it can be charged by a standard USB port from a computer, these typically provide lower current (500 milliamperes or 1 ampere). As a result, if the iPad is turned on while being charged with a normal USB computer port, it will charge much more slowly, if at all.

Apple claims that the iPad's battery can provide up to 10 hours of video, 140 hours of audio playback, or one month on standby. The battery loses capacity over time and is not designed to be user-replaceable. As in the battery-replacement program for iPod and the original iPhone, Apple will replace an iPad that does not hold an electrical charge with a refurbished iPad for a fee of US$99.

 STORAGE AND SIM

            The iPad was released with three options for internal storage size: a 16, 32, or 64 GB flash drive. All data are stored on the flash drive and there is no option to expand storage. Apple sells a camera connection kit with an SD card reader, but it can only be used to transfer photos and videos.

The side of the Wi-Fi + 3G model has a micro-SIM slot (not mini-SIM). The 3G model may be used with an AT&T data plan that does not require a contract,  Unlike the iPhone, which is usually sold locked to specific carriers, the 3G iPad is sold unlocked and can be used with any compatible GSM carrier. In the U.S., data network access via T-Mobile's network is limited to slower EDGE cellular speeds because T-Mobile's 3G Network uses different frequencies.

   APPLICATIONS

           Apple developed the iPad with an improved functionality over that of the iPhone and iPod Touch. The iPad comes with several applications such as Safari, Mail, Photos, Video, YouTube, iPod, iTunes, App Store, iBooks, Maps, Notes, Calendar, Contacts, and Spotlight Search.  These applications were borrowed from iPhone’s third generation OS, but improved for the iPad. However, the iPad doesn’t run the iPhone’s 3.1.2 OS and neither the Mac OS X, but an improved version of the third generation iPhone OS, iPhone OS v3.2. Moreover, the iPad will receive the latest iPhone OS, iPhone OS 4 within the fall of 2010.
The iPad syncs with iTunes on a Mac or Windows PC. Apple ported its iWork suite from the Mac to the iPad, deleting several features in the process, and sells the Pages, Numbers, and Keynote apps in the App Store.  Although the iPad is not designed to replace a cellphone, a user can pair it with a Bluetooth headset and place phone calls over Wi-Fi or 3G using a VoIP application.