There are four techniques to represent knowledge:
Relational knowledge: In this representation, knowledge is represented as a set of relations, similar to relations that are used in the database
Inheritable knowledge: In this representation, knowledge is represented using objects, their attributes and the values of the attributes
Inferential knowledge: In this representation, knowledge is represented in the form of first-order predicate logic
Procedural knowledge: In this representation, knowledge is represented as a set of rules and a rule describes an action to be performed when a condition is met.