Without this deal, Iran could double its capacity to enrich uranium in a short time. With it, it must reduce that capacity immediately and sharply.
Without this deal, Iran could continue to rapidly develop advanced centrifuges. With it, its program will be significantly constrained.
Without this deal, Iran could expand its existing stockpile of enriched uranium. With it, that stockpile will be reduced by 98 percent, and it will be capped at that level for 15 years. Iran will also be required to get rid of its 20 percent enriched uranium, which is most of the way to bomb material.
Without this deal, Iran could produce enough weapons-grade plutonium each year for one to two nuclear weapons. With it, Iran will not produce any weapons-grade plutonium.
Without this deal, Iran could take the steps necessary to produce a nuclear weapon. With it, Iran is prohibited from pursuing any of these steps.