Mobile phone features (2.0), dual line support, infrared, Bluetooth (2.0) and WiFi connectivity, NFC, instant messaging, Internet e-mail and browsing and serving as a wireless modem. The first smartphone was the Nokia 9000 Communicator in 1996 which added PDA functionality to the basic mobile phone at the time. As miniaturization and increased processing power of microchips has enabled ever more features to be added to phones, the concept of the smartphone has evolved, and what was a high-end smartphone five years ago, is a standard phone today. Several phone series have been introduced to address a given market segment, such as the RIM
Mobile phone overuse on the human's psychological mind and social communication. Mobile phone users may encounter stress, sleep disturbances and symptoms of depression, especially young adults. Consistent phone use can cause a chain reaction, affecting one aspect of a user's life and expanding to contaminate the rest. It usually starts with social disorders, which can lead to depression and stress and ultimately affect lifestyle habits such as sleeping right and eating right. According to research done by Jean M. Twenge, a professor of psychology at San Diego State University, there is a correlation between mobile phone overuse and depression. According to Twenge and