Objects are blocks of program code that define things that contain the data they need to function and the methods they need to change their data. Objects are also capable of responding to events. Data are stored in fields and properties and the methods act upon them to create desired effects. Objects are declared as classes with all the features of object-oriented programming to make them flexible and powerful. All objects descend from TObject. Components are objects that can appear on forms but are not visible, while controls are visible objects on forms such as buttons and images. Components are true OOP objects because they encapsulate data and methods, they inherit data and behaviour from their ancestors and they can be variations on a theme or polymorphic.
| TForm | TStream | TDataSet |
| TException | TCustomControls | TScrollingWinControl |
| TCustomEdit |