You can use an FTP client to transfer pictures and files to and from your computer to an FTP server including Payloadz.
Most web servers offer FTP capability, so you can use FTP to easily transfer your web site files from your computer up to the web site. It is generally easier, faster, and more efficient to transfer your files via FTP than other methods.
There are many public FTP servers available from which you can download files from. FTP Extreme allows you to connect to servers immediately after you install it.