Use TADCustomMemTable to manage data in the client memory and optionally exchange the data with a DBMS. 

In general, TADCustomMemTable is an in-memory dataset. It may be populated directly by the code at run time without connection to a database. For example: 

  ADMemTable1.FieldDefs.Add('id', ftInteger);
  ADMemTable1.FieldDefs.Add('name', ftString, 20);
  ADMemTable1.Open;
  ADMemTable1.AppendRecord([1, 'MySQL']);
  ADMemTable1.AppendRecord([2, 'SQLite']);

And TADCustomMemTable may be populated from a database using TADTableAdapter and TADCommand components. That may be considered as an advanced technique, because TADQuery may be used for most DB data exchange operations. 

This class hides some of properties, allowing to control visibility of properties by descendant classes. End users should use TADMemTable.

TADCustomMemTable = class(TADAdaptedDataSet);

TADMemTable, TADDatSTable, TADCustomTableAdapter

See AnyDAC\Samples\Comp Layer\TADMemTable\Main sample for details of how to setup TADMemTable. 

See AnyDAC\Samples\Comp Layer\TADMemTable\MasterDetail sample for details of how to work with master-detail relation.