It is crucial to understand the structure of a network stack because data must traverse multiple layers, each with specific responsibilities, to ensure successful communication before it reaches a program at its destination.
It is important to understand the network stack because it is the basic foundation of networking, without the foundation, you can't understand the further details of networking. Each layer of the network has a specific functionality and based on these functionalities data transmission occurs.
It is important to understand the structure of a network stack because our data travel trough these layer from application layer to physical layer not once but twice . That's why its a fundamental knowledge that need to known like how data traverse from application layer to physical layer.