It is a prayer that honors the Virgin Mary and seeks her intercession. The specific timing of when it is prayed may possibly differ based upon specific or community procedures. The hymn is sung (using the English translation "Hail, Holy Queen enthroned earlier mentioned") by a choir of nuns inside https://encapsuladosvip.com/vita-pro-nobis-descubra-os-beneficios-dessa-incrivel-planta-medicinal/