in looking at the DB website, for example on 9/7 a train leaves
Munich at 8:46 and arrives in Calw at 12:07, it mentions ICE690, RE1
and RB74, are those the train numbers ?
those are indeed the train type and number. That means you will be on 3 trains in decreasing order of speed and increasing order of number of stops before yours. You will change twice.
ICE is Inter City Express, the fastest long distance train type. Stops at only major cities and interchanges.
RE is Regio(nal) Express, stays within a region and skips some local stops.
RB is Regio Bahn, the milk train which stops at every anthill.
ICE690 originates at München Hbf and goes to beyond Berlin. Because it originates in Munich relatively early in the day you have a reasonably good chance of it being on time leaving. I make no guarantees that it will stay on time. It makes 3 stops on the way to your change point of Stuttgart Hbf, stopping at a Munich suburb, Augsburg (a particularly nice and historic town) and Ulm, of the very high steeple and the end of Bavaria. How Stuttgart is on the way from Munich to Berlin will best be left to the boffins at DB
You have 16 minutes to change at Stuttgart, a doddle if you're on time (no longer a given with DB long distance) onto the RE1.
The RE1 originates about an hour before Stuttgart and you're only going 3 stops in half an hour.
Then the change at Pforzheim Hbf. You only have 6 minutes there so I hope all the other dominos are in a row, or you'll be waiting for the next RB. The RB74 makes 7 stops in its half hour, originating in Pforzheim Hbf so it will be waiting for you.
