The definition given to a feedback form is one that is collecting information from known participants. This is typically, but not limited to, a single stage application that does not require any additional actions. An example of this type of application might be a form that captures feedback on the quality of a software product from its users/consumers.
The Invited/Guest User use case is less common and not very well understood. It allows you to send a special link to an external user (one that might not normally have access to HCL Leap) and allow them to review or update your form. An invite link can not be provided for the initial (Start) stage only for the subsequent stages.
Update / Tracking
This type of application is most commonly used as a way tracking some type of information. A simple example might be for an organizer to have a single form for tracking potluck attendees and dishes they are bringing. A more complex example would be a system used for tracking customer engagements and activity.
This example shows how you can create tracking applications. The tutorial will walk you through how you can build the UI in one application and a second application where the deal records are created and updated. This way you have one database for the deals - a single version of the truth if you will - and another database to keep an audit trail which tracks of all changes and updates.
Customer / Lab Involvement Tracker
The following example shows a customer tracking form that has a record locking feature implemented so that only one person can update a record at a time.
This type of application is a bit more complex in that it exercises dynamic workflow where the next person in the workflow is determined at run-time.
Query / Dashboard Style Apps
Custom UI with Data Stored in other App(s)
You may consider this type of approach if you need to customize how your application data is exposed to your audience. The primary approach to handling submitted data is to use View Responses but that can be somewhat confusing to novice or non-technical users. What you may want to do is simplify what your audience sees and what they can interact with.