Knowledge may be (I) Declarative (II) Procedural (III) Non-procedural.

• Only (I) above

• Only (II) above

• Only (III) above

• Both (I) and (II) above

• Both (II) and (III) above

...
These various knowledge representations exist.

Declarative knowledge

includes details about things and occurrences as well as facts and relationships.

Procedure knowledge

is the understanding of how to carry out tasks, such as problem-solving techniques.

Knowledge

that does not cleanly fall into either the declarative or procedural categories, such as knowledge about how to make decisions or create concepts, is referred to as non-procedural knowledge. So this means knowledge is Declarative and Procedural.