Scarl is correct. A "holiday" in Britain is the same as a "vacation" in America. They refer to time taken off from work or school. They can also carry the more specific meaning of a trip taken during such a time. In America, the word "holiday" is much more commonly associated with a calendar celebration such as Christmas, Halloween, etc. The connection is that with many such holidays, people are given time off from work or school. "Trip" and "journey" are similar but the devil is in the details. As Scarl said, a journey is typically thought of as longer. I would also say that a "trip" is normally smaller scale than a "journey." You might even hear someone say "I'm going on a trip to the store," referring to something very quick. "Journey" is never used like this. I think of a journey as something more epic and certainly longer, as stated before, than a trip. And sometimes it is not meant literally, and more means a period of development in someone's life, like "It's been a hard journey getting this far." Hope I helped. :)

Well,I'm not a native speaker but holiday sounds more British English and vacation sounds like American English.And a journey is longer than a trip.