The use of mobile devices rather than only desktop computers for games, Internet access, general computing and as a terminal to the corporate network. We are in the post-PC era today.
It Began With the Web
When smartphones and tablets came on the scene in the late 2000s, the mobile browsers rendered the same Web pages, and soon enough, mobile versions of the very same websites.
A Lot of Execution Is Done in the Server
The same Web protocol (HTTP) is widely used by mobile apps to access Internet-based servers for information and computation. Multi-core CPUs and increasing clock rates in mobile device make them generally only one generation behind desktop and laptop computers in performance.
A major concern with mobile devices in the post-PC era is battery life as smartphones and tablets have replaced desktop computing for many users, especially for those who never worked with a computer before. See how to select a mobile device
and post-digital era
Desktop Computing Is Not Dead
Although sales of Windows and Mac computers may not keep up with the volume of mobile devices, large-screen desktop computing is by no means as defunct as media articles love to tout. There is no substitute for a 27" screen and a quality, full-size keyboard. Both desktop and mobile devices will thrive for decades to come. See BYOD