Until 2012, there was really only one big dog in the Italian rail travel game. Now, with the introduction of Italo train service by the private company called Nuovo Trasporto Viaggiatori, travelers have a few more options.
NTV began operation in April of 2012, and offers only high-speed train service—Italo's trains run at speeds up to 190 MPH (300 km/h). Italo trains have three classes of service, called Smart (roughly akin to second class), Prima (first class), and Club (premier first class), although all levels come with leather seats and free WiFi. Prima and Club class also come with free drinks and snacks, and Club class passengers get a personal touch-screen entertainment system at each seat.
Italo trains serve Turin, Milan, Venice, Padua, Bologna, Florence, Rome, Naples, and Salerno (with a few smaller points in between), but they don't always use the same train stations that Trenitalia uses. This isn't a big deal, unless you're planning to transfer from an Italo train to a Trenitalia train—or vice versa. Be sure to check the station names on your tickets.
Photo credits: Marco 56