Cloud file transfer works by storing the files on a remote server and then enabling users to access them when required. Cloud service providers often use multiple layers of protection to ensure that the files are safe. Dropbox, OneDrive and iCloud are three cloud storage services that are available for free, as of 2016.
Depending on the exact service and the user's preferences, a cloud storage service may either upload the user's files automatically or require the user to upload manually. The user can then download the files himself or allow others to access the contents of his cloud storage. The user can either change the sharing settings that apply to certain files to allow others to access them at any time or generate links that only enable those with the link to download the files. Likewise, the owner of the cloud storage can make it so that others can only view the files but not edit them.
Throughout the process, the cloud service provider uses multiple layers of SSL protection to ensure a safe transfer. When using Dropbox, for instance, the file first goes through an SSL layer and reaches the processing servers which then encrypt the data. The servers then send the files to the storage servers through another layer of SSL. When the user, or someone else that the user chooses, initiates a download, the file goes through the two SSL layers before reaching the target device.