A network topology diagram provides a visual representation of a network's physical and logical layout, which is crucial for understanding how the network is structured and how different components are interconnected. Updating this document ensures that anyone looking at it will accurately understand the current state of the network. An Acceptable Use Policy (AUP) is important for outlining the rules for using the company's network but doesn't provide a network layout. An Incident report is used for documenting specific incidents after they occur, and a Regulatory compliance document refers to legal compliance requirements, not the layout of the network.