Cloud Computing is a software infrastructure that is used to store data on servers so that they can be accessed easily with the help of internet. It is categorized into two parts, front-end, and backend. The front-end allows you to access the data that is stored, however, the backend is where the data is stored.
To get started with the cloud, read this Cloud Computing Tutorial. Also, take a look at this video tutorial to get a better knowledge of cloud computing: