How to connect old IMAC to new iMac(M1) by cable?

mr-ed, You are going to need a thunderbolt cable and a dongle to connect the old imac to the new one. Thunderbolt 3 to Thunderbolt 2 Adapter and a Thunderbolt 2 cable. I would also recommend rebooting your old imac in Target disk mode. Your old mac will appear as an external drive to the new mac.

Hope this helps.

Paul

No, you will need a USB 3 cable and a multitude of adapters. If you follow the method I suggested you can bypass the expensive cables and adapters and be up and running in a couple of hours.

Please follow the steps in Setup Assistant and Migration Assistant , why very simple it works 100% of the time, overall is the easiest method to use and overall is the quickest method of migrating.