Share 'Jigs, Reels, Hornpipes, Walk Arounds'

In Irish Fiddle Music I believe the following is fairly accurate.  A Jig is in 6/8 time  A Reel is in 2/4 time  A Hornpipe is in 2/4 with a different accent.   In Minstrel Banjo   A Walk In The Parlor Jig   could be considered 6/8 time but most other Jigs would not be.   Do the terms Jig, Reel, Hornpipe, Walk Around, etc. have any meaning regarding the structure of the musical piece?