A mapping cell is an atomic relation contained in an Alignment.
A cell specifies source and target entities, a relation function and possibly parameters for the function.In the image below a mapping cell is represented as it would be displayed in the Alignment view. In the example the type t1 from the source schema is mapped to the type person in the target schema, the relation is represented by the Retype function.
Creates a person instance for each t1 instance in the source data set.
In certain cases, as shown in the image below, it is necessary to map two different relations to a target entity. In that case it is important to understand the concept of cell priority.
The case of two relations mapped to a target entity. Cell priority is mandatory.