synching 2 imac computers

I have 2 imacs; one is Active and contains the data I want. The 2nd has been idle for several months. I want to put the 'idle' one back in use and want it to contain the the data that's on the 'active' imac. I have time capsule but I'm wondering if I can connect the 2 computers and update the data files in that manner.

I'm running Sierra 10.12.26

Thank you.