Many Italian churches are dedicated to the Mother of God Mary and thus have a "SANTA MARIA" (sometimes, as here, increased to "SANTISSIMA") in their name. This church in Scilla has the addition "IMMACOLATA", so it is dedicated to the "Immaculate Conception" of the Mother of God.
This term, which today may sound a bit theoretical and difficult to understand, is intended to say that the Mother of God was freed from the beginning by the grace of God from the burden of original sin - which otherwise every person carries within themselves. This meant that when the archangel later announced to her in Nazareth that she would give birth to the Son of God, she was willing to answer YES of her own free will.
In 1854, Pope Pius IX elevated this article of faith to dogma. The feast for this occasion - and at the same time the patronage of this church here - which in the Catholic liturgy is called the "Solemnity of the Immaculate Conception of the Virgin Mary without Original Sin" is celebrated annually on December 8th.