You can delete some files by mistake or your computer can crash. In these case you lose photos, important documents and other data. I very important to have a copy of these files - this means to make a backup.
Dropbox will backup your desired files on their secure servers for free up to 2GB. For larger hard disk space you need to pay, but 2GB is enough to have a copy of your important files.
How it works
1. Install Dropbox software from this page.
2. After installation run the program and create an account with username and password from program's interface. You will have a short and useful tutorial about how to use it.
3. Installing Dropbox will create automatically a folder on your computer, named Dropbox. Here you will copy, move with drag and drop or delete files. All files from this folder (from your computer) will be uploaded automatically on Dropbox third-party servers. You can move this folder where you want on your hard disk.