MktgRob 7 Nearly a Posting Virtuoso

I am workiing with a client who has just completed a project with a customer who sells pre-paid calling cards on consignment. It was explained to me that the codes for the individual cards are stored in a database in the cloud and that my client had to integrate their solution to communicate with this database.

As I am relatively new to cloud computing and this scenario of a database in the cloud sounds really interesting, I was wondering if anyone has a quick non-technical explanation of how a database in the cloud works?