When you specify a source property and a target Endeca property or dimension to map to, you are creating an explicit mapping.
In general, this is the type of mapping Endeca recommends you use. However, Endeca also offers some advanced techniques that allow you to automate the mapping process. These techniques are intended to facilitate the process of building prototypes and should not be used for building production-ready implementations.
See the related topics for detailed explicit mapping procedures.