Slots and facets are used in

Answer: Frames

Explanation: Frames are a knowledge representation structure where each frame models a stereotypical object or situation. Slots are the named attributes of a frame, and facets are the pieces of metadata about a slot (for example default values, constraints, types, or inheritance rules).

• Semantic networks: Use nodes and labeled links to show relations between concepts; they do not organize attributes with slots and facets.

• Rules (production systems): Represent knowledge as condition-action pairs or if-then rules; they rely on pattern matching and do not use slots/facets as frame structures do.

• Conclusion: Slots and facets are characteristic of frames, so the correct answer is Frames.