Modal Versus Non-Modal Forms

Non-modal forms cause an extra system load compared to modal forms. The non-modal forms generally run in parallel to support the same end-user task, so the allocation of the same resources also changes, resulting in contention.

A modal form allows the focus to change to another form only after the modal form has finished executing. In principle, all form-specific resources, such as internal memory, are released before exiting to the next form.

A non-modal form allows the focus to change to another non-modal form while it is still active. In this case, all resources required by both forms remain allocated.