For a business, the electricity that flows from an outlet seems endless. And water will stream out of the tap without worry — businesses pay only for what they use. But computing power hasn’t been so seamless. Data storage hardware can accept only a finite number of bytes. When businesses enter into monthlong server contracts, it takes days to add more capacity. If usage surpasses a server’s capacity, it will crash. Cloud computing, the super-hyped tech term of the moment, aims to change that.