What does the cloud offer?
Well lets define what the cloud is, and start by what it's not.
If you have all your IT on-site at the office, then none of it's in the cloud. Computer servers, and all the like hardware associated located with it on-site, is not the cloud. You may have remote access to it via the Internet, or a private network connection, however they are on-premise. They are not cloud, or cloud-based.
Cloud or cloud-based is when IT infrastructure is located off-premise, usually in a third party service data centre. A cloud service provider will manage the hardware, or said another way, free you from managing physical hardware of servers, network devices and data storage on-premise. The cloud industry advocates it saves business the costs associated in doing the "racking and stacking" of hardware.
So what is the advantage of the cloud? Basically business can look to manage their IT costs as a fixed expense rather than large capital outlays that depreciate. And for most businesses they'd prefer not to have the large capital outlay and the ongoing cost to manage it too. It ages quickly, is expensive to own and operate, and prone to failure.
The cloud also provides a much more flexible approach to scaling IT resources to meet changing demands. The cloud calls this being agile. Ultimately the cloud offers value when planned and managed well.