The Fuel and Ignition maps in the ECU allow you to edit down to the Individual Cylinder Maps. There can also be Group Maps which provide other groupings of Fuel and Ignition Maps e.g. Gear Groups or Upper and Lower Injectors.
When editing maps and/or using the Woolich Racing AutoTune it is much easier to work with a unified set of maps. This allows you to edit one map and the changes are applied to all of the associated maps.
If you unify Fuel Cylinder maps, when you edit the Fuel Maps you will only need to change one Fuel Map and the changes will be applied to all of the cylinder maps.
You can configure Fuel and Ignition map unification settings in the "Bin File Configuration" screen shown below. You can gain access to this screen by clicking on the "Configuration" button on the main screen in WRT.

'Bin File Configuration' window showing Fuel/Ignition Map Unification settings
Unifying and 'Maintain cylinder offset' presents you with one map to change, and the software handles the differences between the individual cylinders automatically. If the factory setup is for each cylinder to get a different amount of fuel, then the software will handle all those differences in the background, and you just need to change one map.
Unifying and setting it to a particular cylinder, also presents you with one map to change, but will make all cylinders use that same cylinder's map. Any changes are applied across all cylinders evenly, with the same values (same map for all cylinders).