Thanks Larry. I do know what 'via' means (I did Latin at school for a start! Now I am an English language teacher :)), but I just don't yet see why, if there is a STAR selected, plus a transition, the pilot would be asked for input for a 'via' as well. I suppose there must be more than one way to get to the transition point - that makes sense from the use of the word 'via' at least, but as I still can't locate (on the map) any of the transition or via points I am offered by the FMC (which is quite possibly me being a bit dense, I wouldn't deny!) I still have no way to choose one transition, or 'via' over another. Is the via an actual point, like a waypoint, or a path, like an airway? (I assume the former, but it could be either. Using your analogy of a car - not so good for me as I have never driven a car in the 60 years of my life! - I can go from Southampton to Luton, via Staines (point), or via the M25 (route))?
I choose SIDs and STARS using LittleNavMap, which highlights the chosen route. I then adapt my flightplan as needed (deleting now obsolete waypoints, which are within the area of the SID or STAR), but after that I am working in the dark when trying to select which transition and/or via to input into the FMC.
Thanks again... I'll have a look at your links too, of course.