Field symbols and data references allow you to access data objects dynamically in ABAP programs. Unlike static access to a data object, where you need to specify the name of the object, field symbols and data references allow you to access and pass data objects whose name and attributes you do not know until runtime.
You can regard a field symbol as a symbolic name for a data object. Field symbols use value semantics. When you address a field symbol, the system works with the contents of the data object assigned to it, and not with the contents of the field symbol itself.
Data references are pointers to data objects. Data references use reference semantics. Data references are the contents of data reference variables. When you access the reference variable, you are addressing the data reference itself. To access the contents of the data object to which a data reference is pointing, you must dereference it.