Network architecture plays a crucial role in determining network performance. Firstly, the design and layout of the network, including the placement and configuration of network devices, impact the efficiency and speed of data transmission. Secondly, the choice of protocols and network technologies affects factors such as latency, bandwidth, and data throughput. Thirdly, network architecture influences the scalability and capacity of the network, ensuring it can handle increasing traffic and user demands. Lastly, security measures implemented within the network architecture help protect against threats and ensure data integrity, further enhancing network performance.