as my previous reference to FTP was not to your liking, and you wanted and explanation of FTP (according to the rather abrupt, negative and private repu, i mean 'message' that I got from you), try
THIS one instead.
silly me for thinking that an explanation of an FTP app on your machine could be answered by the application's help file, or indeed by the homepage of the application's vendors (which my first link gave many examples and links to)... oh well, we live and learn.