A component can be almost any program element that you want to manipulate at design time. Creating a component means deriving a new class from an existing one. You can derive a new component in several ways:

• Modifying existing controls
• Creating windowed controls
• Creating graphic controls
• Subclassing Windows controls
• Creating nonvisual components

The following table summarizes the different kinds of components and the classes you use as starting points for each.  

Component creation starting points  

You can also derive classes that are not components and cannot be manipulated on a form, such as TRegIniFile and TFont.