What exactly is this/does it do?
Sorry, I don’t quite understand your question. Do you mean, what does a patron saint do?
A patron saint can be the saint you were named after (For example, my patron saint is St. Therese the Little Flower because I was named after her.) You can have a special devotion to this saint and they can work marvels for you in your lifetime.
Patron saints can also be associated with certain groups of people or things. For example, St. Jude is the patron of lost causes, St. Albert the Great is patron of scientists. It means that different things fall under their special protection, such that people facing a terminal illness may ask St. Jude for prayers of consolation and strength or a miracle. You never know what might happen.
Great answer, Chris! :yup:
And basically they are our prayer partners in heaven.
When a person is baptized, a litany of the saints in included during the prayers. We ask these saints to be present in the life of the one about to be baptized with their intercessory prayers, so naturally it would follow to also ask their patron saint to be there to do it as well. One of the many gifts our church provides us the faithful.