If you've linked a document to another document using the function for
adding movements, data about the linked document will be displayed in this panel.
From Movements 
Lines with the From Movements icon contain basic information about documents FROM which the document in which you have opened the Links tab has been created. If it is a collective invoice, the internal issue documents included in it will be listed here.

To Movements 
Lines with the To Movements icon contain basic information about document TO which movements in the document in which you have opened the Links tab have been added. It it is an internal receiving document, the collective invoice that it was added to will be listed here.
