A mobile device or handheld computer is a computer small enough to hold and operate in the hand. Mobile devices are typically battery-powered and possess a flat-panel display and one or more built-in input devices, such as a touchscreen or keypad. Modern mobile devices often place emphasis on wireless networking, to both the Internet and to other devices in their vicinity, such as headsets or in-car entertainment systems, via Wi-Fi, Bluetooth, cellular networks, or near-field communication.
An iPhone (smartphone) and iPad (tablet)—two examples of mobile devices
Smartphones, handheld mobile devices
Smartwatches, handheld mobile devices
A computer is a machine that can be programmed to automatically carry out sequences of arithmetic or logical operations (computation). Modern digital electronic computers can perform generic sets of operations known as programs. These programs enable computers to perform a wide range of tasks. The term computer system may refer to a nominally complete computer that includes the hardware, operating system, software, and peripheral equipment needed and used for full operation; or to a group of computers that are linked and function together, such as a computer network or computer cluster.
A human computer, with microscope and calculator, 1952
The Ishango bone, a bone tool dating back to prehistoric Africa
The Antikythera mechanism, dating back to ancient Greece circa 150–100 BCE, is an early analog computing device.
Charles Babbage c. 1850