Is Cloud a device?

Is Cloud a rain droplet? No. It is collection of droplets.

In the same way, IT cloud is collection of nodes, where each node can communicate with each other.

If you had accessed software applications through a network connection, often by accessing data centers using wide area networking (WAN) or Internet connectivity, before 2008, remember that the service provider owned the hardware, meaning, the investment on hardware was done by the service providing company.

Now instead of owning the hardware, company can outsource.

Having said that, customer can access the hardware attributes remotely from any geographical location. 

Please digest the analogy which I am giving now. Say you owned a Maruti 800 car. You used to enjoy the car. But you have to be with car's location to do so. But today, you can enjoy any car at any time, from any geographical area.

Just imagine in same way, for your PC. Somebody else will maintaining your PC. And it will be always up. No down time for your server as there will be back up for the service that you are providing. Of-course, you need to pay for the company who gives this service.

The cloud is just a metaphor for the Internet. In the simplest terms, cloud computing means storing and accessing data and programs over the Internet instead of your computer's hard drive. 

Note: Gartner is the world’s leading research and advisory company, headquartered in US.

Extract from wiki:

By mid-2008, Gartner saw an opportunity for cloud computing "to shape the relationship among consumers of IT services, those who use IT services and those who sell them" and observed that "organizations are switching from company-owned hardware and software assets to per-use service-based models" so that the "projected shift to computing ... will result in dramatic growth in IT products in some areas and significant reductions in other areas."