Understand that a form is used to display and maintain records.
Forms display records one at a time in a format that can be customized.
Rather than reading the data from a table, it can be laid out in a way to suit your needs.
Forms provide a way for users of the database to add or edit data in a simpler fashion than entering directly into a table
An example of a database where a form could be useful is in stock taking.
A table may contain the fields Item Code, Date, Number of units on shelf, Number of units in warehouse.
A simple form can be created for this data, that allows for easy entry of stock inventory.
Bigger businesses tend to use software that automates this process by using barcode scanners that will automatically populate a database, but the principle is the same. Using a form is a cheaper alternative for smaller or growing businesses.