Pope Francis arrives at the Rome’s synagogue, flanked by leaders of the local Jewish community Ruth Dureghello (L) and Renzo Gattegna (R) on January 17, 2016 in Rome, Italy. The visit marks the third time a pontiff has been invited to the synagogue, following on from the visit by Benedict XVI in January 2010 and the historic encounter of Pope John Paul II with former Rabbi Elio Toaff there in 1986.
A synagogue [Greek synagoge: assembly] is a Jewish house of worship and center for religious education. The synagogue has ancient roots. Today it is often synonymous with “temple” and “shul.” But there are differences, outlined here >> http://www.jewishboston.com/Ask-A-Rabbi/blogs/3729-what-s-the-difference-between-a-temple-synagogue-and-a-shul