This paper presents a meta-analysis of dream theory within psychology and neuroscience. The questions it attempts to answer are: what is the neuroscientific basis of dreaming? Why do dreams exist (do they have an adaptive function)? Could dreams possibly have no function? And, what is the best way to interpret a dream? The current analysis presents various theories relevant to each of these questions and compares their viability. It also briefly examines the origins of psychological thought on dreams and, towards the end, outlines the steps and empirical support for a well-regarded method of dream interpretation known as the cognitive experiential model. In the end, the analysis finds that a major likely cause of dreaming is the occurrence of different memory processes during REM sleep, whose activity likely also contributes to dream content. As for adaptive functions, the existing neuroscientific evidence suggests that we are almost certainly capable of learning during dreams and that learning may therefore be one of dreams’ primary adaptive functions. However, due to the scarcity of research on dreams, few of these conclusions can be drawn with overwhelming confidence. Lastly, in regards to dream interpretation, the cognitive experiential model seems to provides a framework for dream interpretation which clients and therapists alike find satisfying and useful.