More and more people like to use cyberspace to store their most frequently used and even the most precious files. If you would like to backup, transfer, or synchronize your important files or valuable data on multiple cloud servers, in the traditional way, you have to do like this:

1. Login a cloud service using your username and password
2. Download the files you want to local drive
3. Login and upload them to other cloud services one after another

When people need to synchronize, backup or frequently share files/data between a variety of devices (including computers and mobile phones), any traditional ways of file transfer are relatively inadequate. For example, a lot of cloud storage services like Dropbox have more and more and increasingly obvious limitations or restrictions. These include: files have to be uploaded to their servers for transfer, very limited disk space capacity, pretty high requirements on Internet connection speed and stability, limitation of transmission speed and bandwidth usage, very few acceptable file types, not high enough security, easy to be blocked by some countries, expensive cost, and so on. Thereupon, Resilio Sync (formerly called BTsync, full name BitTorrent Sync, now Sync for short) came out.

Free web hosts are too numerous to count now, and many of us are using them to store, share or download a variety of documents/files everyday. But, their shortcomings mainly include the following ones:

• Pop up a heap of annoying ads windows
• Deceptive download buttons are around
• Long waiting time difficult to endure