Dropbox is a cloud-based storage service that is ridiculously easy to use.Download the app and drag your files into the newly created folder. That's it; your files are in the cloud and can be accessed from anywhere.It sounds like a simple idea, but back in 2007, when it was released, there wasn't anything like it.Today, Dropbox has around 700 million users and stores over 550 billion files.All these files need to be organized, backed up, and accessible from anywhere. Dropbox uses virtual servers...