The data is hosted in “the cloud”, that is, in a “Data Center” with high security servers, where backups are made every day. In addition, your data will travel encrypted over the internet through the secure https protocol from when they leave your computer to the destination server, so that nobody can read them.
** Here several notes. If you are about to define where you are staying ... and the theme of https is yet to be integrated: But it is what I should put in that question.