SCP is the abbreviation of 'secure copy', while SFTP stands for 'secure FTP'.
The first is used to copy one or more files, often with known names, from host A to host B, whereas the second is mostly used interactively, analogue to an FTP client. SCP will always work out of the box and has little in the field of tweakable options. SFTP can be used with different backends to present the SFTP service to the user. It would even possible to turn it off, though I haven't tried this.
That's the difference in use.
As far as performance goes: ErikA below links to a wikipedia page which mentions SCP is generally faster than SFTP because of a more efficient algorithm in SCP.
SFTP is FTP over SSH so if both servers are servers then both most likely already have SSH (if they are unix servers)
You then need an SFTP compatible client.
Since they are both servers It does not really matter which one has the client and which one has the server.
Typically one would use a client on a client machine, be it windows, Mac or linux to connect to the SFTP server on the server but in your case both are servers? then it really does not matter. one does the connecting while the other does the listening.
Best Answer
SCP is the abbreviation of 'secure copy', while SFTP stands for 'secure FTP'.
The first is used to copy one or more files, often with known names, from host A to host B, whereas the second is mostly used interactively, analogue to an FTP client. SCP will always work out of the box and has little in the field of tweakable options. SFTP can be used with different backends to present the SFTP service to the user. It would even possible to turn it off, though I haven't tried this.
That's the difference in use.
As far as performance goes: ErikA below links to a wikipedia page which mentions SCP is generally faster than SFTP because of a more efficient algorithm in SCP.