Which two statements accurately describe the purpose of the OSI model?

The OSI (Open Systems Interconnection) model is a conceptual framework that standardizes the functions of a telecommunication or computing system into seven distinct layers. This layering helps in understanding the specific responsibilities and protocols at each stage of network communication. Therefore, "Defines the network functions that occur at each layer" is correct because the model clearly delineates what each layer does. By breaking down complex network processes into manageable, independent layers, the OSI model simplifies the explanation of how data moves from a source to a destination, making "Facilitates understanding of how information travels through a network" also correct. "Changes in one layer do not impact other layers" is incorrect because while layers are designed to be somewhat independent, changes in the services provided by one layer can certainly affect the layers above or below it. For example, a change in a physical layer technology would impact the data link layer. "Ensures reliable data delivery through its layered approach" is incorrect because while some layers (like the Transport layer) contribute to reliability, the OSI model itself is a reference model, not a mechanism that ensures reliability. Reliability is implemented through protocols within specific layers.