Linux system, network architecture, TCP/IP protocol, server-side, client-side, router, modem, firewall, network interface card, RJ-45 connector, Cat5 Ethernet cable, Linux terminal, command line interface, coding, C programming language, socket programming, IP address, subnet mask, gateway, DNS resolution, packet transmission, data encryption, secure connection, sysadmin, programmer, desk, keyboard, monitor, CPU, motherboard, circuit board, wires, screws, metal casing, dimly lit background, warm ambient lighting, shallow depth of field.