This feature allows you to save lists and reuse them as options in multiple forms.
Wouldn't it be great if you could just share data to all your forms and update them all at once instead of recreating the same lists? This saves your time!
To start with...
1. Create a form and use the following elements: Single choice, Multiple choice, Multi Product Select, Select dropdown
2. Create a datasource (from Data Sources menu), and fill in label and value
3. Under 'Add new link', select the form and its elements you want to link