I give away knowledge I have attained and earned.. and I '*might* get a treat!!!!' ?
Rapture and glee!
There is your PC, and there is the worldwide Internet.
If something is built in or attached to your PC. Your hard drive, a backup drive perhaps, that is all local to you.
If you have decent security in effect, it is difficult for anyone else to see what is on your computer and any drives you may have connected to it.
Then there is the 'cloud'. That nebulous off-site data haven for everything else in the Universe.
If your files are retained there, you don't need a hard drive. You don't need a computer, for that matter. All you need is a monitor, a keyboard and a connection to the 'cloud', and all manner of things are yours.
MicroSoft can rent you access and you can fill out Word, Excel, and PowerPoint presentations online, without having to buy a license. Adobe can lease you a PDF writer. Apple can store your iTunes music, Oracle or Intuit can maintain all of your financial files for you. They do maintenance. They do security updates. They can cushion and protect you from all of the bumps and bruises of lost files, hackers, inadvertent deletions, etc.
All for a nominal fee, of course.
Oh, and they control the access. Which can limit new ideas from being available/distributed.
(Picture a movie deal allowing only access to 20th Century Fox films for downloads, because Fox paid your ISP a preferential fee.)
And, of course, they can sell what they wish to anyone for a fee.
(Data Mining in the 21st century is BIG business. Marketers want access to people by demographics, geography, likes, wants, interests, websites visited, etc.)
Plus, naturally, as with any centralized system, it is subject to various forms of breakdowns wiping out potentially millions of people's data in the blink of an eye.
Additionally, while their servers may be relatively secure, today, the hackers of tomorrow will have much more sophisticated computers and codes. Rendering this years files subject to complete snooping and hijacking.
But the people who market this 'cloud' assure you those things are well known, and are all being addressed.
I recommend a healthy skepticism.