Many years ago Internet Service Providers (ISP's) and internet hosting companies languished in profits when users used the ISP's servers and hosting services to hold emails and files. At that time, these services were simply known as FTP (File Transfer Protocol) and just plain email (or POP3 email) services.
During the noughties (2000-2009) or the oo's (ooh's) some may call it, Microsoft, developed their server systems and brought us newer technologies that allowed small and medium enterprises to host their own mail and filing systems, in the form of Microsoft Servers or Microsoft Small Business Servers (SBS), running Microsoft Exchange and Sharepoint services.
This left many an ISP with little joy as they saw their profits from hosting, eroded by users and enterprises migrating away from their hosted services and starting up their own Microsoft server systems.
So the question was, how do the hosting companies get users to come back to their hosted systems, which they have spent years and many dollars building.
A lightbulb moment occurred and now we have CLOUD computing.
Cloud computing is really nothing new when you think about it, hosted email systems offsite and hosted file systems offsite, it is essentially the old FTP system and email hosting that the ISP's used to provide, all over again.
Innovative companies such as Google, Dropbox, Picasa etc, have improved the interface between these old services and built an easy to use, easy to view, and sometimes, automated synchronizing system that allows users to move their files in a simple and efficient manner between their PC's and the internet, something they learned from Microsoft (during the days when PC's were difficult to use, Microsoft created Windows and made computing easy), so Google, Dropbox and others have made the transfer of files between the PC and the internet or their cloud file servers, easy.
Though this is a simplistic view on what cloud computing is and how it has evolved, it is quite a logical evolution of the system we once knew and hated because of how difficult it was, but are starting to love because of how it has grown in terms of ease of use. Though this is the case, do I endorse the use of Cloud computing? That is a thought for another time.