Keywords
FTP
FTP (File Transfer Protocol). A internet protocol to upload files to a remote computer running an FTP server.
The internet providers run web servers to deliver content over the http internet protocol. The web installation additionally runs a ftp server so that a user with the according permissions can upload the content files to the web server.
On Linux just use the command ftp on the command line. On Mac use a FTP application like CyberDuck (search for it on versiontracker). On Windows you are on your own to choose from the variety of available ftp programs.