Connected Lookup column is an extension of the regular SharePoint lookup columns. It introduces such advanced features as cascading filtering, integrated item creation and auto-complete functionality.
Associated Items column can be used within the source list of any lookup column to display all items referencing the current item. For instance, List A is the source list for the lookup. List B contains a lookup column referencing List A. Some items in List B have a certain item from List A selected as the lookup value. An Associated Items column in List A will display those items when viewed from the parent item forms.
Simply create a new Associated Items column in List A. Under Child list select List B. It will automatically present the lookup column in List B pointing to List A. Save the Associated Items column settings and add it to the form using Form Designer. You will now be able to view all related items for each item in List A.
