The OKY2101 is an Ethernet module manufactured by OKYSTAR, designed to be used with SPI and W5100 to shield the Arduino application. It uses a sophisticated networking protocol known as W5100 to make it easier for users to access wired networks from within their Arduino setup. It features a wide range of advantages, including built-in TCP/IP protocol stack and network application expansion capability, as well as secure Ethernet connection, built-in socket buffer, and support for UDP and TCP packets. Additionally, it provides a built-in 10/100 Ethernet transceiver which allows for a high speed connection of up to 100Mbps. This module also features power saving design and easy-to-install hardware, making it an ideal solution for anyone looking to quickly and easily implement a reliable and secure wired network connection on their Arduino application.