A mobile phone (also known as a cellular phone, cell phone
and a hand phone) is a device that can make and receive telephone calls over a
radio link whilst moving around a wide geographic area. It does so by
connecting to a cellular network provided by a mobile phone operator, allowing
access to the public telephone network. By contrast, a cordless telephone is
used only within the short range of a single, private base station.
In addition to telephony, modern cell phones also support a
wide variety of other services such as text messaging, MMS, email, Internet
access, short-range wireless communications (infrared, Bluetooth), business
applications, gaming and photography. Mobile phones that offer these and more
general computing capabilities are referred to as smartphones.
The first hand-held cell phone was demonstrated by Dr Martin
Cooper of Motorola in 1973, using a handset weighing around 1 kg. In 1983, the
DynaTAC 8000x was the first to be commercially available. In the twenty years
from 1990 to 2010, worldwide mobile phone subscriptions grew from 12.4 million
to over 4.6 billion, penetrating the developing economies and reaching the
bottom of the economic pyramid.
Cell phones are used for a variety of purposes, including keeping in touch with
family members, conducting business, and having access to a telephone in the
event of an emergency. Some people carry more than one cell phone for different
purposes, such as for business and personal use. Multiple SIM cards may also be
used to take advantage of the benefits of different calling plans—a particular
plan might provide cheaper local calls, long-distance calls, international
calls, or roaming. The mobile phone has also been used in a variety of diverse
contexts in society.