Answer:
Pyramid model
Step-by-step explanation:
The pyramid model of differentiating information system is the oldest and most commonly used system of differentiating information systems because from its origin it was built in a way that it gives priority to how important a system while classifying them.
The most relevant information system is found at the top of the pyramid and the least relevant system is found at the bottom of the pyramid.this classification makes it easy for collecting information from the systems based on relevance and also for the purpose of improving systems that are lacking in one way or the other.