jour·ney
n. pl. jour·neys
1. The act of traveling from one place to another; a trip.
2. A process or course likened to traveling; a passage: the journey of life.
http://dictionary.reference.com/search?q=journey
Basically, a journey is a phase of experience. It can be either physical, imaginative or inner. The meaning of a journey can be very broad but it basically has to do with travel or personal change. It has to do with experience over time and the process of development/growth. Thats generally what journeys are about, but it depends on what type of journey.
Physical journeys: movement from once place to another
Inner journey: personal experience, growth, development over time
Imaginative journey: journey that is thought about/imagined but doesnt actually happen in real life
I hope that'll help a bit