The way the ticket form works out of the box is that any user can submit a ticket whether they have an account or not. When your ticket form allows un-authenticated users to submit tickets this is referred to as a Public Form
Most companies will have it as a Public form but if you would like to change that setting so that only authenticated users can submit a ticket then you can change that setting here.
There are two differences when a user is authenticated or not authenticated in SeamlessDesk when submitting a ticket.
When a user is authenticated they do not need to enter an email address to submit a ticket. We already know who they are and where they belong.
When a user is un-authenticated then the user will have to manually enter their email address.
This scenario works well when a company has many users from multiple areas or tends to have individual customers. Where this would not work well is when you are an internal I.T. company and deal with the same users daily.