1. Knowledge can be defined in many ways such as "what we know", "justified true belief", or a "framework for evaluating new information". 2. Knowledge exists in both explicit and tacit forms - explicit being codified and able to be shared formally, tacit being highly personal and difficult to share. 3. Nonaka's SECI model describes how knowledge is converted between tacit and explicit forms through socialization, externalization, combination, and internalization.