Unmounting passport from iMac

If I unmount my external drive from my iMac, I am backing up to it, while I am travelling to put somewhere else so I dont loose all my data should something happen, can I just plug it back in when I return and the passport will continue backing up where it left off ?
Thanks
(back up newbie!)

Hello,

What backup software are you using on you Mac?

Time machine

Hello,

Time machine should resume the backup when you plug the drive back to the computer. That is if you never changed that in the time machine settings.

Thank you. I haven’t changed any settings so I think I am good to unplug !