Congratulations on the new iMac! Going from a 2006 Intel iMac to a new M4 iMac is definitely a major upgrade.
A few things to add to batorousseauevan's reply to you ...
For a Mac that's nearly 20 years old, I actually wouldn't recommend using Apple's Migration Assistant. While it can work in some situations, it may also bring over older applications, settings, and system components that aren't compatible with Apple Silicon Macs. Since many applications from a 2006 Mac won't run on your new iMac anyway, it's generally better to transfer only your personal data.
Your best options are:
Option 1 (as suggested by batorousseauevan): Use an external hard drive or USB flash drive
- Copy your documents, photos, music, videos, and other personal files from your old iMac to an external drive.
- Connect that drive to your new iMac. If the drive has a USB-A connector, you'll simply need a USB-A to USB-C adapter or a USB-C hub with USB-A ports. Here's an example that you can get from Amazon.
- Copy the files onto your new Mac and then reinstall current versions of the applications you still use.
Option 2: Use your existing Time Machine backup (if you have one)
There were a few 2006 iMac models, but I believe the latest version of macOS that it could run was 10.7.5 Lion (only on the Late 2006 models). The Early 2006 models could only be upgraded to 10.6.8 Snow Leopard. Regardless, both of these macOS versions support Time Machine.
So, If you've been backing up your old iMac with Time Machine, you can browse the backup and manually copy your personal files to the new Mac rather than restoring the entire system.
Option 3: Network transfer
If both Macs can connect to the same network, you may also be able to share files over your local network. This avoids needing additional cables but can be slower, especially with an older Mac.
Again, If your goal is simply to get your documents, photos, music, and other personal files onto the new iMac, an external drive is typically the easiest and cleanest approach.