Knowledge can be categorized into several types, with the most common being declarative knowledge and procedural knowledge. Declarative knowledge refers to facts and information that can be stated or declared, such as knowing that Paris is the capital of France. This type of knowledge is often about "what" we know and can be easily communicated. On the other hand, procedural knowledge involves knowing how to perform tasks or activities, like riding a bike or playing a musical instrument. This type of knowledge is more about skills and processes, often acquired through practice and experience. It answers the question of "how" to do something effectively.