A general connection to your FTP server, (file transfer protocol) is not secure. When you connect without using SSH, both your userid and password are sent to the server “in the clear” or in other words, without any encryption. Would you post your
username and password on a public website for all to see?
Furthermore, the files you are sending are unencrypted too, so if they contain passwords, sensitive customer data, etc, you are putting that on the public site as well. Anyone using Cain & Able type software could sniff your information relatively easily.
How to use Secure FTP or SFTP?