What you need to know about the preliminary U.S.-Iran agreement signed by Trump

In this photo provided by the Islamic Republic News Agency (IRNA), Iranian President Masoud Pezeshkian displays a memorandum of understanding signed with U.S. President Trump aimed at ending the war and launching negotiations on a broader agreement, in Tehran, Iran, early Thursday.

Here's a look at the preliminary agreement between the U.S. and Iran, and the challenges that remain to find lasting peace.

(Image credit: Iranian Presidency Office via AP)