A mobile phone (also called mobile, cellular phone, cellphone or handphone)[1] is an electronic device used for full duplex two-way radio telecommunications over a cellular network of base stations known as cell sites.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 common components found on all phones are:a rechargeable battery providing the power source for the phone functionsan input mechanism and display to allow the user to interact with the phone. The most common input mechanism is a keypad, but touch screens are also found in some high end smart phones.basic mobile phone services to allow users to make calls and send text messages.All GSM phones use a SIM card to allow an account to be swapped to between devices. Some CDMA devices also have a similar card called a R-UIM
