This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
According to what I have understood: Its on demand service- Be it hardware or software resources. So we have Software as a Service(SaaS), Platform as a Service(PaaS). So the cloud takes care you your computing needs- You just have to specify your requirements. Good examples of this are- Amazon Cloud, Salesforce (SaaS), even Google with its Google Apps.