Smart phones are hand-held personal computers with mobile operating system and integrated mobile broadband cellular network connection for voice, SMS and Internet data communication; most (if not all) smart phones also support Wi Fi. Unlike larger tablets, smartphones are usually pocket sized. They can run a variety of software components, called "applications.". Most basic applications (such as event calendar, camera, web browser) are pre installed in the system, while others can be downloaded from official sources such as Google play store or Apple App store. Applications can receive bug fixes and other functions through software updates; similarly, the operating system can be updated. The modern smartphone has a touch-screen color display with a color graphical user interface covering the front surface, enabling users to use the virtual keyboard to type and press the icon on the screen to activate the "application" function. Now, mobile payment has become a common topic in most smartphones.

Nowadays, smart phones have basically met the needs of users for telephones, digital cameras and cameras, GPS navigation, media players, clocks, news, calculators, web browsers, hand-held video game machines, flashlights, compass, address book and notebook. Shooting, digital message, event calendar, etc. A typical smartphone will include one or more of the following sensors: magnetometers, proximity sensors, barometers, gyroscopes or accelerometers. Since 2010, smartphones have adopted integrated virtual assistants, such as apple Siri, Amazon Alexa, Google assistant, Microsoft Cortana, blackberry assistant and Samsung Bixby. Most smartphones produced since 2012 have high-speed mobile broadband 4G LTE.

In 1999, NTT DoCoMo company of Japan released the first smart phone to achieve large-scale adoption in a country. By the late 2000s, smartphones had barely grown. Smartphones expanded in the third quarter of 2012. In the third quarter of 2012, 1 billion smartphones were used worldwide. At the beginning of 2013, the global sales volume of smart phones exceeded that of feature phones