Modular and Ethernet connector jacks, including RJ45 and RJ11 types, are widely used for data, voice, and network connectivity. RJ45 jacks support Ethernet and LAN applications, while RJ11 is typically used for telephone connections. These connectors are available in through-hole and surface-mount versions, with shielded or unshielded options to suit various environments. Common in telecom, networking, and industrial systems, they offer reliable, standardized interfaces for twisted-pair cable connections.