It's all arbitrary. I think there is a lot of crossover between long distance, road cycling, touring, etc. For instance...if I do a 5 or 6 day, 150 mile a day credit card tour and race other people on a road racing bike am I doing a long distance ride, a bike tour, or a stage race? Ultimately its all just riding a bike, and probably kind of hard to draw a definitive line between the different types.