Answer:
As an Irish dancer there are many differences. The biggest one is the hornpipe is a hard shoe or heavy shoe dance where as the reel is soft shoe. Another one is that the music is different. The reel only has one speed 113 and the hornpipe has multiple. The hornpipe has a slow and fast version. The more advanced dancers dance the slow version. The fast version is speed 138 and the slow is 113. You can find all of the music on YT. My personal favorite is the reel :)