posted 18 years ago
SCP is done over a secure (i.e., encrypted) connection; hence the "S" in SCP. FTP is unencryted (although you can SFTP, which is FTP over SSH, and thus encrypted).
Also, I don't think anonymous file transfers are supported in SCP, because you need to have an account on the target machine.
Going out on a limb here, I will speculate that SCP only works in Unix-like operating systems, not on Windows, while at least an FTP client is built into all common operating systems.