What does it mean by "Follow-up Masters"?
I can't speak for the Czech system, but in the Netherlands a follow-up master is a master program specifically designed for students who completed a certain bachelor program.

All students who graduated from that bachelor program (and selected similar programs at other Dutch universities) are accepted into the master automatically. If you did not graduate from one of these bachelor programs (for example, because you studied abroad), you have to apply to the university for a certificate of admission (bewijs van toelating). In that case, the university decides whether you can be admitted anyway, can be admitted after following a so-called homologation program1, or cannot be admitted.

One reason these programs exist is that the introduction of the bachelor-master system in the Netherlands is quite recent (2002). Before, universities offered longer (~5-year) programs that resulted in a degree comparable to a Masters. With the introduction of the new system, many universities simply split their existing programs into a bachelor program (typically 3 years) and a "follow-up" master program (1-2 years).



1 The University of Twente describes homologation courses as:


  Homologation courses (bridging courses) are advanced bachelor courses that you will have to follow if they contain essential knowledge for your master’s programme. [...] The courses depend on the chosen specialization and they have been selected by the Admission Committee.