Related to this: What are the things that “The Force Awakens” borrowed/parallel from “A New Hope?” (which asks which things the two films have in parallel/similarity):
Which things/characters do The Force Awakens and A New Hope have which appeared in both films?
You can include items from Episodes V/VI as well, as long as they are explicitly marked as such
WARNING: The answer contains spoilers to The Force Awakens!
To clarify: This question is specific to items which are actually in-universe the same item in both films. It does NOT include items that are of the same kind/type but in-universe are different items - in other words, two droids or ships of the same type that aren't explicitly the same exact droid/ship are offtopic .