Munich to Vienna on Railjet

It's the same train, don't read too much into it.

I have taken that train . You will print your ticket at home after you make the purchase . Be aware that you will be required to produce the credit card you used for the purchase for verification by the conductor on the train

Trains often change designation along their routes, particularly if they cross a border. For instance, the direct trains from Munich to Prague run in Germany as ALX trains but sometimes change to EX or EC in the Czech Republic.

Other times a train might change designation because it combines with another train or splits off part of the train.

I've even seen cases where different ends of a train had different designations. For instance the night train that used to go from Amsterdam to Prague had sleeper cars designated as CNL, After Berlin you could only get off the night train, you could not book a place on the night train from, say, Dresden to Prague. But there were also coaches (seats only) on the same train which were designated as IC, and you could book a seat on the IC from Dresden to Prague.

By the way, RJ63 is a specific RailJet that leave Munich Hbf at 9:30. There are other trains between Munich and Vienna that day designated RJ, but no other train designated RJ63.

Thanks.

As Tom mentioned above, I read too much into the verbiage used on the DB website.

when the train arrives in Salzburg, the DB website says "Train continues as RJ 63". Perhaps I am reading too much into this, but why is there the need to say that?

Well, that's an Austrian train operating from Bavaria across the border into Austria. Unlike "European" trains (EC's), which retain their number over the entire trip, it may have a different number in the DB and the ÖBB train registry. So, the system shows a train number for the German and one for the Austrian leg even if they are identical in both registries and for both legs.

"why is there the need to say that?" For practical purposes, it makes no difference after you board.

Thanks.

So the most important variable is that the train in Munich will in fact say "Railjet 63" or "RJ 63"; as opposed to having a separate name.

Well, the salient information is the »continues as«. You could, e.g., find the info »RJ 63, continues as RJ 1«. But seriously, the vital information for you is provided in the step before: changes of train: 0. Your question comes up only, if you dive into the depth of the system and check out the route of the train en detail. That might if interest when planning some zigzagging trip, but it's unnecessary for a simple point to point trip. so, relax and have a pleasant trip!