Chiesa (pronounced kee-ess-ah) and duomo (doo-oh-moh) are terms that Italians use to refer to churches. I have always used 'duomo' when speaking about a church assuming every Italian did too, until recently. A friend with Italian roots asked me what 'chiesa' meant--his family used the term when speaking of the little churches "back home." I had to admit that I had never heard the term before.
Come to find out, chiesa translates to church; duomo translates to dome. There are several large churches, primarily in the larger cities, that stand as famous landmarks today, such as St. Peter's Basilica in Rome and Basilica of Santa Maria del Fiore in Florence (picture left). Most of these are referred to as duomo--they each have a dome creating a major architectural feature. No less significant or impressive are other churches found throughout the smaller towns of Italy that do not have domes (like the Basilica of Santa Margherita in Cortona, pictured below) called chiesa. 
