Prior knowledge refers to the information and understanding that a person already possesses before encountering new information. This existing knowledge can come from personal experiences, education, or cultural background. It plays a crucial role in how individuals interpret and integrate new concepts, making learning more effective. When learners engage with new material, their prior knowledge helps them make connections and build on what they already know. For example, a student familiar with mathematics will find it easier to grasp algebra concepts than someone with no background in the subject. This connection enhances comprehension and retention of new information.