Due to filesystem permission restrictions and PHP Safe Mode
restrictions. For all users to utilize the Joomla! installers an FTP
layer exists to handle filesystem manipulation.
Enter an FTP username and password with access to the Joomla! root
directory, this will be the FTP account that handles all filesystem
operations when Joomla! requires FTP access to complete a task.
For security reasons, it is best if a separate FTP user account is
created with access only to the Joomla! installation.