Yeah, that's how I've always interpreted it -- they call them "series" instead of "seasons" because they often commission them one at a time, each one treated as a one-and-done, until and unless the next one is commissioned. Sometimes they even have different titles, like the four series of Blackadder. Although there are other shows that are ongoing multiyear serials, like the original run of Doctor Who; I would imagine that's also true of soaps like Eastenders or Coronation Street.
