A mobile phone, cellphone, hand phone, also sometimes shortened to just mobile, hand or pocket phone, and sometimes called by other names (e.g., walkie-talkies), is a small portable phone that can communicate over a wireless radio frequency network while the user is traveling within a specified telephone service area. The two major types of mobile phones are generally CDMA, which is a single-tone tone telephony signal technology, and GSM, which uses a Code Division Multiple Access, a digital-signal technology, for multi-tasking purposes. Mobile phones can be used with a wireless service provider (WSP) either on a dedicated network or as an unlicensed service where WSPs provide local and long distance services at lower costs. These phones also come with various additional features such as a camera or video camera, music player, Bluetooth technology, a Global Positioning System, or a SIM card for global wireless communication.
Cell phones, as their name suggests, are used to make and receive telephone calls; however, the use of the cell for communication has evolved to include other functions such as Internet usage. These advanced mobile phones are equipped with various applications including email, Internet browsing, text messaging, Internet telephony, and game use. Some cell phones also allow the use of miniature personal computers such as Pocket PCs or laptops. The advent of downloadable software and the invention of the cellular phone service providers have further increased the possibilities for mobile phones.
Mobile service providers offer two different kinds of plans for their customers: contract plans and pay as you go. The contract plan of a contract mobile phone enables the user to make and receive unlimited calls in a specific area for a fixed monthly fee. The user has to sign an agreement with the service provider and may have to pay a security fee. The pay as you go option enables the user to buy a pre-paid cell phone and the user can call a specified number of times for free. Several service providers also allow customers to change their mobile numbers frequently. With growing popularity, more people are opting for a mobile phone.