Another great feature in the latest release of Adobe Photoshop CC is Linked Smart Objects. Linked Smart Objects enable you to place another file inside of a composition as a smart object. Any time that the linked file is saved, those changes are automatically propagated to the linked documents that you have open. (If they’re not open, you will be prompted the next time you open the file.)
For example, you can place a .ai Illustrator file inside of a PSD as a Linked Smart Object, and when you update the content in Illustrator, the content in Photoshop is automatically updated. Check out the video below for more detail.
Be sure to check out the Creative Cloud learning resources to learn more about Linked Smart Objects.