To be honest, I've heard this track before, but then I haven't realize that it cames from an opera. It was couple of years earlier when I was listening Sarah Brightman's album called Symphony (2008). The lyrics for this song was written by an Italian lyricist Chiara Ferrau. I do like the Brightman's song but frankly speaking I prefer the original Intermezzo, without lyrics of course.
If you are interested in her version of this piece, I refer you to the link below.
Now I would like to explain you what the Intermezzo is. Well, opera's composers wrote sometimes the Intermezzi as connecting pieces between acts of operas. In this sense an Intermezzo is similar to the entr'acte (Intermission). And the most popular intermezzo is probably the Intermezzo from Cavalleria rusticana by Pietro Mascagni. Besides, it's very interesting that this opera is often performed in so-called Cav/Pag double-bill with Pagliacci, an opera written by Ruggero Leoncavallo. In fact, last year when I went to the Grand Theatre to see this opera, there was two performances one after antother.
I really recommend you to see both of them, but especially Cavalleria rusticana, even for this one short Intermezzo. In my opinion, this is very sublime and exceptional piece and I'm not surprised that this is one of the most popular Intermezzi (but probably the most).