Types of Train Services in Barcelona

• Long-Distance Train Services in Barcelona All of these services are run by RENFE. This includes the high-speed AVE.
  You can book RENFE train services here Train Tickets in Spain (book direct)
  
  There are two main RENFE train stations in Barcelona. Read about Barcelona Train Stations
  

• Regional Train Services in Barcelona This is where things get a little confusing.
  One regional train in Barcelona is Cercanias RENFE Barcelona. Though also run by RENFE, the Spanish train operator hasn't had the good sense to incorporate it into their main search engine. Frustratingly, you have to visit a different site to get these timetables.
  
  You are most likely going to want to use the Cercanias to get to Barcelona Airport and Sitges. If you've been frustrated looking for Sitges trains on the RENFE site, this is why - you've been looking in the wrong place.
  
  The other regional train service that you might need to use in Barcelona is the FGC. The FGC acts like an underground metro in the city, but it morphs into a regional service when it leaves the center. You're most likely to use the FGC to get to Montserrat (though you could always take a Guided Tour of Montserrat.