TPersistent is the ancestor for all objects that have assignment and streaming capabilities. TPersistent encapsulates the behavior common to all objects that can be assigned to other objects, and that can read and write their properties to and from a form file (.xfm or .dfm file). For this purpose, TPersistent introduces methods that can be overridden to:

• Define the procedure for loading and storing unpublished data to a stream.
• Provide the means to assign values to properties.
• Provide the means to assign the contents of one object to another.