A mobile phone (cellular phone, cell phone and a hand phone) is a device which can make and receive telephone calls over a radio link while moving around a wide geographic area. It does so by connecting to a cellular network provided by a mobile network operator. The calls are to and from the public telephone network which includes other mobiles and fixed-line phones across the world. By contrast, a cordless telephone is used only within the short range of a single, private base station.

Modern mobile 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 smart phones.

The first hand-held mobile phone was demonstrated by Dr Martin Cooper of Motorola in 1973, using a handset weighing 2 1/2 lbs (about 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,

(Thanks: www.wikipedia.com)