Three-tier architecture, network, futuristic, digital, computer systems, servers, routers, switches, wires, circuit boards, microchips, screens, keyboards, mice, complex network topology, nodes, connections, data flow, packets, protocols, firewalls, routers, switches, hubs, modems, network interface cards, Wi-Fi signals, Ethernet cables, fibre optics, cloud computing, virtual machines, cyberpunk, neon lights, dark background, misty atmosphere, high-tech, sci-fi.