Will VPN only work on one computer at a time

Will the VPN impact another computer in the house if I only install it one? I don’t want to cause problems with my partner’s computer if she doesn’t want to use VPN for any reason or if she decided to use a different VPN service.

It will only work on the system it is installed on.

“System” meaning computer, or meaning the Network we are logged into?

The specific machine.