Dream is an imagination that comes from our mind. Usually, it is unreal and weird. Most dreams and reality relate to each other. We have dreams at nights, always because we think something a lot in days; we really wonder to get something; we meet excitements in our lives; or we have a very deep impression or memory that is not easy to forget.
First of all, we may have dreams at nights if we think or worry something a lot in days. When we meet something that is very important for us in lives, we will think it seriously and carefully. Then we may dream it at nights. For example, John is a student in college and he needs money to pay for his school. He applies for a new job and he will have an interview next Monday. As we can see, John really needs this job to support his life and the job is very important for him.
He thinks it and worries his interview a lot and he even imagines the situation that will happen and what kind of questions that manager will ask him. Then he has a dream at night about his interview. He dreams that the manager asks him about his education, families, personal ability and work experiences. He answers everything perfectly and the manager smiles to him.
Secondly, we may imagine and dream something that is very hard or impossible for us to get in real life. We wonder them, but they are difficult to get. We still wish to own them one day. For example, Peter is a shoe warehouse worker. He has a poor living and his earning only can support himself because he gets little payment. His girlfriend leaves him because he does not have enough money...