A priori knowledge refers to information that is known independently of experience. This type of knowledge is often associated with logical reasoning and mathematical truths, such as 2 + 2 = 4. It is considered universal and necessary, meaning it does not rely on sensory experience to be validated. In contrast to a posteriori knowledge, which is based on empirical evidence and observation, a priori knowledge is derived from intellectual deduction. Philosophers like Immanuel Kant have explored the significance of a priori knowledge in understanding concepts such as space and time, arguing that certain truths are inherent to human reasoning.