Touchscreen

A touchscreen is an input device that allows a user to interact with a computer or mobile device by touching the display screen.

History
The earliest versions used beams of light that were projected across the screen surface. Interrupting the beams generated an electronic signal identifying the location of the screen. Software would interpret the signal and perform the required operation.

Usage by Apple
The first device from Apple Computer to use some form of touchscreen was the Newton MessagePad H1000, first released to the public in August 1993. However, its touchscreen required a passive for detection through, like that of a Wacom tablet. During the 1990s, Apple had also developed stylus-based Mac prototypes, such as the PenLite, which were not released to the public. The first touch-based device from Apple that did not require a stylus was the 2nd generation iPod, which was released in July 2002 with a Touch Wheel for simple circular gestures. In 2007, Apple introduced the iPhone, the first device with a multi-touch display that used to detect complex gestures from multiple fingers without the need for a stylus. In October 2016, Apple released a MacBook Pro with a small multi-touch-capable Touch Bar above the keyboard.

Articles

 * Apple’s Curious Resistance To Creating A Touch Screen Mac by Tim Bajarin at Forbes ( 2021-07-07)