It becomes much easier to understand the international negotiations over Iran's nuclear program when you see that each of the issues falls into one (or more) of three overlapping categories: things that are crucial for stopping Iran from getting a nuclear bomb, things that are less important but are just really hard to resolve, and things that mostly matter for appeasing domestic politics in Washington and Tehran.
Those distinctions also help explain why it's been so hard to reach a deal, even though theoretically everyone agrees on the broad concept: that Iran will get relief from international economic sanctions in exchange for accepting limits on its nuclear program meant to keep it from ever developing a nuclear weapon.
Here, then, is a super-simple guide to the eight most fundamental issues under discussion, where the negotiating teams stand on each, and why it matters...
And for those interested in something closer to the original document: Fact sheet from State Department: Parameters of plan on Iran nuclear program