Urbi et Orbi ("to the City and to the World"; literally, " City and to World") denotes a papal address and Apostolic Blessing that is given to the City of Rome and to the entire world, on certain occasions. It was a standard opening of Ancient Roman proclamations.
The blessing is given each Easter and Christmas in Rome from the central loggia of St. Peter's Basilica, at noon. Part of the urbi et orbi blessing is the remission of all temporal punishment due to sin through a plenary indulgence attached to the Papal blessing.
The blessings at Christmas and Easter are broadcast throughout the world by the European Broadcasting Union. The indulgence and remission of venial sins is not only granted to the people in St. Peter's Square but also to Catholics watching the ceremony on television and listening on radio. Before this blessing the Pope gives an address to the crowd and to the world, with seasonal greetings in many of the major world languages.
Urbi et orbi is also used at St. Peter's at the Papal inauguration and, on very rare occasions, as the blessing of pilgrims and during the Holy Year (Jubilee).
The main phrase of the blessing ends Et benedictio Dei omnipotentis, Patris et Filii et Spiritus Sancti descendat super vos et maneat semper (And may the blessing of Almighty God, the Father, the Son and the Holy Spirit, descend on you and remain with you always).
Read more about Urbi Et Orbi: Latin Text of The Blessing, English Translation, Older Practice, Term