ZD Net explains:
Since the dawn of cloud computing, one theme has been a constant: the idea that demand can be dynamic and elastic, that you pay only for the resources you use, and that the service is delivered on demand. But does cloud computing today live up to that promise? Recent developments show that there may be a different way to satisfy that expectation.
Serverless computing exposed
Going back to basics, unless you are buying off-the-shelf commercial software services, cloud computing has always required the buyer to size and specify a server - CPU, RAM, storage, and so on. But there are times when this is not appropriate, with some observers going as far as describing the idea of having to think in terms of servers - even if they are virtual - as a left-over artifact of traditional datacentres.