Not at all, SFTP (SSH File Transfer Protocol, an SSH2 protocol extension) doesn't have anything to with FTP (outside of the name), and only require an ssh serve

Not at all, SFTP (SSH File Transfer Protocol, an SSH2 protocol extension) doesn't have anything to with FTP (outside of the name), and only require an ssh server that supports it - OpenSSH does for example. You might be confusing it with FTPS (FTP Secure, or FTP over SSL/TLS). (To add to the confusion, there are some FTP servers that also support SFTP - so they act as SSH servers)