Unwanted link between desktops
We bought a new desktop. We are using the existing iMac as well as the new one. When either of us opens/closes an app it shows/disappears from the Doc of the other computer. So there must be some link between the two computers that we don't want to have... but don't want to loose any files either of us have created in the fix either. One thing I know is they both have the same Apple ID. Is this the problem? How do we fix this unwanted connection? Thank you for your reply.
iMac 27″