A mobile phone, also known as a cellular phone, cell phone, cellphone, handphone, or hand phone, is a portable telephone that can make and receive calls over a radio frequency link while the user is moving within a telephone service area. It is sometimes shortened to simply mobile, cell, or just phone. The radio frequency link establishes a connection to a mobile phone operator's switching systems, allowing access to the public switched telephone network (PSTN). Because modern mobile telephone services are based on a cellular network design, mobile phones in North America are referred to as cellular phones or cell phones. Text messaging, MMS, email, Internet access, short-range wireless communications (infrared, Bluetooth), business applications, video games, and digital photography are all supported by digital mobile phones (2G) in addition to telephony. Feature phones are mobile phones that only have those characteristics; smartphones are mobile phones that have much more powerful computational capabilities.