The term sub form or subform is used when building an application when you embed one form (data entry or data view) into another. Showing data in a parent/child relationship sometimes is called a hierarchical form or a master/detail form. Sub forms are very effective to show data where there is a one-to-many relationship between them. Today, we are going to create this type of screen in a real-world application. This type of scenario is something you will want to build in many of your applications.
https://youtu.be/e7lgFxx-43E