A mobile phone (also called mobile, cellphone or handphone) is an electronic device used for mobile telecommunications over a cellular network of base stations known as cell sites. Mobile phones differ from cordless telephones, which only offer telephone service within limited range through a single base station attached to a fixed line, for example within a home or an office. Low-end mobile phones are often referred to as feature phones, whereas high-end mobile phones that offer more advanced computing ability are referred to as smartphones.

A mobile phone allows its user to make and receive telephone calls to and from the public telephone network which includes other mobiles and fixed line phones across the world. It does this by connecting to a cellular network owned by a mobile network operator. A key feature of the cellular network is that it enables seamless telephone calls even when the user is moving around wide areas via a process known as handoff or handover.

In addition to being a telephone, modern mobile phones also support many additional services, and accessories, such as SMS (or text) messages, email, Internet access, gaming, Bluetooth, infrared, camera, MMS messaging, MP3 player, radio and GPS.

The first hand held phone was demonstrated by Martin Cooper of Motorola in 1973, using a handset weighing in at two kilos. By the end of 2009, the number of mobile cellular subscriptions worldwide reached approximately 4.6 billion, penetrating the developing economies and reaching the bottom of the economic pyramid.