Often, the answer is probably yes. However, there are some caveats.
Don't install older versions of macOS than what your computer shipped with
When you get a brand new Mac from Apple, it has a specific version of macOS installed on it, and further, a "build" that is specific to that exact model of Mac. If you install an older version or build of the OS, for example by cloning your older Mac to it, then it may behave unexpectedly, or it may not boot at all. If your new Mac is brand new, use Migration Assistant to migrate your data to your new Mac.
If your "new" Mac is just different, but not really hot off the lines, then cloning another Mac to the new Mac may work fine. When cloning your source Mac to your new Mac, be sure that your source Mac has been updated to at least one later release than what came on the newer Mac. For example, if your newer Mac came with 10.9.3, update your source Mac to 10.9.4 before migrating. If such an update is not available, use the Migration Assistant instead.
Some of your preferences on macOS are considered "host-specific"
Preferences such as these will be ignored if you boot another machine from your cloned operating system and data. For example, the screen saver preferences are host-specific — if you boot another machine from your bootable clone and the screen saver kicks in, you will notice that it has reverted to default settings. Do not fear that you have lost any data, your original preferences will be "restored" when you boot again from your original Mac. To learn exactly what preferences are host-specific, hold down the Option key and choose "Library" from the Finder's go menu, then navigate to Library > Preferences > ByHost.
Network settings may not be respected on another Macintosh
In addition to application-specific preference files, the network configuration of one Mac may not be accepted by another Mac. macOS network settings are stored in /Library/Preferences/System Configuration/preferences.plist, and CCC will copy that file unless you explicitly exclude it. Sometimes a Mac will respect the settings configuration file from another Mac, but often there are enough differences in the networking hardware configuration that macOS decides to ignore the contents of that file.
So how can I find out if it will actually work?
Determining whether this type of clone will work for you is really easy — simply boot the destination Mac from the source Mac or from a backup of the source Mac:
- If both the source Mac and the destination Mac have Firewire or Thunderbolt ports, boot the source Mac into Target Disk Mode by holding down the "T" key on startup, then attach the source Mac to the destination Mac with a Firewire or Thunderbolt cable. If not, attach a backup of the source Mac (or the source Mac's hard drive in an external hard drive enclosure) to the destination Mac with a Firewire, Thunderbolt or USB cable.
- On the destination Mac, open the Startup Disk preference pane in the System Preferences application and set the source Mac's volume as the startup disk, then click the Restart button.
If the destination Mac booted from the source Mac's installation of macOS, then it works! Open CCC, then clone the source Mac's disk to the destination Mac's internal hard drive. If the destination Mac could not boot from the source Mac's installation of macOS, use the Migration Assistant to transfer your user data and applications instead.