If you are coming from programming background , definitely you have heard about auto-mapper which basically maps to fields between two objects if the field name and type are the same.
If you don't have programming background, nothing to worry about as it is simple.Basically the requirement is mapping two fields in two objects if the name and type are exactly the same.
CPQ Twin Fields
To give you an example , consider you like to have access to a field you created or existed in Product object in Quote Line. Based on the above, auto mapping is available between these two objects, and if you have a field called "MyField__c" on product as a text or picklist that wanted to map to Quote line , go to Quote line object and create exactly the same field name "MyField__c" with text or picklist, and that's it.
Now if you set some value to that field in product the the value automatically will be available on Quote line, this value can be used later for some filtering or ...
