Sorry, In Visual Basic you can create a parent form and a child form, or multiple parent forms and multiple child forms with their own parents. What that means is the child forms will reside in the parent forms.
These types of applications are called MDI applications (Multiple Document Interfaces)
You can create a MDIparent using Code, Settings or adding a new object then click MDIParentForm.
Visual Inheritance is what occurs when a form inherits the objects/Controls of a form, you can do this with code as well.
There is plenty of documentation over at MSDN.
If you need more specific help, I am sure someone will answer.