Module Assignment
From Joomla! Documentation
This part of the screen gives you access to a list of the site's modules as shown below. Checkbox to show only modules already assigned to this menu item. If unchecked(default), all modules available to assign to this menu item type.
File:Help-4x--menu-item-module-assign.png
- Module. Name of available modules to display with them menu item type. Click to open popup window to assign or assign module to the menu item type. Using this pop-up modal window, you can assign the module to this or any other menu item and also enter the module's position and other options.
- Display. The Display column indicates whether this module will display on this menu item with yes or all. Note - this column is not updated until you save the menu item by clicking save on the top toolbar.