What changes in technology have affected the world in the late 20th and early 21st centuries?

The advent of Internet social networking and mobile phones has changed how often humans interact with each other and how they stay connected. Multitasking and filling up time with communication technology challenges actual productiveness. The use of the postal service to mail cards and letters, telephone books, newspapers and telegrams have plummeted. Book stores and music stores are no longer needed. The Internet has changed the way political campaigns are conducted, and people can diagnose their own medical problems or search for free legal advice on the Web.
Wi-Fi technologies change how public transportation works. Robotics has changed the workplace providing for some tasks to be completed by automated systems. Applications and online shopping allow purchases to be made using a bar code app or PayPal. Technology has made wristwatches obsolete since electronic devices have clock displays. The foundation of privacy principles are forever changed with photo-sharing sites such as Instagram and Flickr. People sleep less, work less and spend less time physically together socializing and communicating when using technology.