The scp command allows you to copy files over ssh connections. This is very useful if you want to transport files between computers. The scp command uses the ssh command to authenticate.
Some times you are not able to do scp from host A to host B for example but you can do scp from B copying data from host A.
The basic syntax is like this:
When you are login HostA and you copy files to HostB
scp file username@hostB:/path/../../
scp user@RemoteHost:/path/file /path/new_location/on local server