"File Transfer Protocol (FTP) was once the most widely used protocol for transferring files between computers. However, because FTP sends authentication information and file contents over the wire unencrypted, it's not a secure way to communicate. Secure Copy (SCP) and the more robust SSH File Transfer Protocol (SFTP) address this security concern by providing data transfer over a fully encrypted channel. You can use these alternatives for transferring files securely over the Internet or any other untrusted network.
"Both SCP and SFTP rely on Secure Shell (SSH) as their underlying protocol. SSH establishes a secure and encrypted channel of communication between computers using authentication and encryption based on Public Key Infrastructure. SSH uses encryption for the authentication data exchanged to set up the session and the subsequent data transfer..."
