They reduce the knowledge necessary to use the system. Strictly speaking, forms are not necessary. A person can do most everything via the Database Window using raw tables, filters, queries, etc. The switchboard should lead to other forms.
Forms are objects in the database.
Technically, they are container objects. They contain other objects called controls or control objects . A menu of choices. Forms to view data, add new records, edit records, delete records. Supplies information but does not allow adding or editing data.