Cloud is an umbrella term for many services, including SaaS and virtualization--anything but traditional computing behind the walls of your own data center. If you're worried about being behind the cloud curve, don't be.
CIOs recognize this latest hype cycle all too well. When client-server computing was all the rage in the early '90s, every vendor slapped the term onto its marketing pitch whether it fit or not. Then it was data warehousing lining up to provide a single view of all your customers at the touch of a button. Next came ERP systems intended to replace the disparate best-of-breed software across business operations.
All of these hype-cycled technologies eventually had a significant impact on corporate computing environments, but invariably at much greater complexity and expense than initially promised.
Source: CIO