Was bedeudet 'as' in Delphi?

[Ignazo]

Delphi-Quellcode:

procedure TPanelX.InitializeControl;
begin
  FDelphiControl := Control as TPanel; //<== Was passiert hier?
  FDelphiControl.OnCanResize := CanResizeEvent;
  FDelphiControl.OnClick := ClickEvent;
  FDelphiControl.OnConstrainedResize := ConstrainedResizeEvent;
  FDelphiControl.OnDblClick := DblClickEvent;
  FDelphiControl.OnResize := ResizeEvent;
end;