Sounds like it's an S-Bahn, an urban or suburban train. "SBA” is not a company but seems to be Eurail's own abbreviation for S-Bahn. Eurail is valid here because this S-Bahn is run by DB and DB is one of the participating companies in Eurail.

In THIS area indeed DB runs the S-bahnen (a kind of inbetween for metro and long distance trains-they never wait for connections and run strictly ev 20/30 mins). But NOT always in the many other big cities in DE-others may have that contract. Mostly they go from main station (in tunnel beside)-like a metro underground and have many stops in the centre-so great for passholders going there. The U-Bahn (which you will also see in all these big cities) is urban transit and NOT included.

U has always U in blue, S is always in green.

Thank you rvdborgt.

I hope it is really the S-Bahn under the guise of eurail’s abbreviation for S-Bahn aka SBA. One last question, if I am in front of the Information Guess Booth at the Frankfurt Airport Regional HBF, will those people be able to tell me that this SBA is same as S-Bahn?

thanks much

You don't need to ask, all trains there are included in the pass.

For Germany, by the way, the DB Navigator app is much better for travel information. It's more up to date and has real-time information.

Thank you mcadv and rvdborgt