The Fourth Major Era of Computing Kicks In

[Commentary] We’re now on our fourth major era in computing. The original mainframe computer of the 1960s automated back offices and transactions, bringing efficiency and lowering costs. That cycle ended in the early 1990s when the personal computer picked up steam. By the mid-1990s the Web was helping to automate interaction between companies and their customers, allowing people to buy goods and services through the magical Internet. The mobile era began this summer, as there are now more mobile users than desktop users, with 1.8 billion surfing the Web on their smartphones. Having a personal computer in your pocket is changing the tech world because, unlike a computer, a smartphone is always there when you need it.

[Kessler is a former hedge-fund manager]