Does SCP between 2 machines copy file to the current machine in the background?
Solution 1:
If it's about scp OpenSSH secure file copy then the answer is in man 1 scp:
-3
Copies between two remote hosts are transferred through the local host. Without this option the data is copied directly between the two remote hosts. […]
So the answer is no, unless you used -3. The option is useful if the two end hosts cannot communicate directly. Examples: link 1, link 2.
According to the changelog the option was added in OpenSSH 5.7/5.7p1 (2011-01-24).