Is there a difference between a Praeludium and a Praeambulum?

We get our word 'preamble' from 'praeambulum'. This word appers to have been used by a number of Baroque composers (mostly Germanic composers it seems) for the first movement of a suite of pieces for organ (usually). I don't think there is any real difference between the two terms. A more modern example of interchangeable terms would be 'overture' and 'prelude' for the opening piece of music before an opera.; there is no real difference, just a preference as to terminology.