Why we back up
Miládka remembers everything in a folder on your computer. That's normally fine – until something happens to the computer. Theft, spilled coffee, a failed disk. Then everything you've told her over the months is gone.
Backup solves it: after every piece of work, Miládka puts a copy on the internet, into your private account. If you lose the computer, you get a new one and download Miládka back exactly as she was.
Bonus: with backup you can have Miládka on a second computer too – say at home and at work. She makes sure both know the same things.
Nobody else sees your data. The account is yours and private. Miládka stores your files in it the same way you have them on your disk – just additionally.