Exponent can share content sources with its modules. From the module settings, you can choose to aggregate existing content. On the Aggregation tab, you'll see a list of all similar modules you can pull content from to share its content with the module you are creating. This will allow you to update a module in one place, and the changes will take effect wherever else the module is being aggregated.
This text module in particular is being shared across 3 pages located under Other Cool Modules > Navigation Module: Sub Page 1, Sub Page 2, 4th Level Page. If you edit the content in this module, the changes will be applied to the text modules on all other pages sharing the source of this module.