elasticity

I've heard many people using both terms interchangeably. However, in my opinion there is difference between them: SCALABILITY - ability of a system to increase the workload on its current hardware resources ( scale up ); ELASTICITY - ability of a system to increase the workload on its current and additional (dynamically added on demand) hardware resources ( scale out ); Elasticity is strongly related to deployed-on-cloud applications. Have I got the difference between these two non-functional software characteristics right? May someone give specific examples, so we could draw more distinctive

Is there a way do do dynamic elasticity in Windows Azure? If my workers begin to get overloaded, or queues start to get too full, or too many workers have no work to do, is there a way to dynamically add or remove workers through code or is that just done manually (requires human intervention) right now? Does anyone know of any plans to add that if its not currently available? There's a Service Management API, and you can use that to scale your application (from code running in Windows Azure or from code running outside of Windows Azure). http://msdn.microsoft.com/en-us/library/ee460799.aspx