The Module List form can be opened from Accounting menu > Accounting Periods > click Close Modules button. This form is used to manage the posting of transactions per module. It is more like you are allowed to do everything on any modules except POSTING.
This form lists all the modules that comprise VisionCore. You can use the Open checkbox to allow or not allow posting of transactions in a financial year for the particular module. When Open checkbox is unchecked, this will close the financial period for the selected module and will prevent particular transactions from being posted.
Toolbar Buttons perform an action on the current record like adding, deleting or saving.
The Save button will save the changes made.
The Undo button will cancel out the last change/s done to the record reverting it to its older state.
The Close button will close the Module List form.
See Ability to close financial period for specific modules to show you how the Module List form works.