The iPad touch Screen input

 When you touch the screen, the iPad's circuitry detects the presence of your finger. It keeps track of how many fingers you have on the screen and where you move them. It also gives the iPad touch the capability of running apps .

The iPad touch does this using a layer of capacitive material under a protective covering. You can readHow Capacitors Work to learn more about them, but the basic idea involves taking advantage of the electrical properties of the human body. When you touch a capacitive surface, the amount of charge it holds changes. This is why devices like the iPad touch require you to touch them with your bare skin -- insulating materials like gloves, pens and styluses don't cause the same changes in the capacitive circuitry.

There are two possible methods the iPad touch can use to measure changes in electrical states:

·         Self capacitance: Circuitry monitors changes in an array of electrodes.

·         Mutual capacitance: A layer of driving lines carries current. A separate layer of sensing lines detects changes in the electrical charge when you place your finger on the screen.

Regardless of which method the screen uses, you change the electrical properties of the screen every time you touch it. The iPad records this change as data, and it uses mathematical algorithms to translate the data into an understanding of where your fingers are. In the next section, we'll explore what the iPad touch does with this data and how to navigate through its features.

The iPad touch Screen output

It serves primarily as a platform for audio-visual media including books, periodicals, movies, music, games, presentations and web content, and is available in black or white. 

The iPad  can be connected with the tv, computer, pc keyboard, digital camera etc.