Descriptive theories are frameworks that aim to explain and categorize phenomena as they are observed in the real world. They focus on detailing the characteristics, behaviors, and relationships of subjects without making judgments or predictions. For example, a descriptive theory in psychology might outline the various stages of human development, such as those proposed by Erik Erikson. These theories are essential for building a foundation of knowledge, as they provide a clear picture of what exists and how different elements interact. They serve as a starting point for further research and can help inform more complex theories that seek to explain why things happen or how they might change over time.