Li-Fi Stands for Light-Fidelity. It is a New Technology and was proposed by The German Physicist Herald Haas in 2011. Li-Fi Provides Transmission of Data Through Illumination and sends Data Through an LED Light Bulb That Varies in Intensity Faster than Human Eye can’t Detect. In This Paper, We will be discussing The Technology in Detail and also how Wi-Fi can be replaced by Li-Fi. Wi-Fi is Useful for General Wireless Coverage within Buildings while Li-Fi is ideal for High-Density Wireless Data Coverage in Confined Areas where There are no Obstacles. Li-Fi is a Wireless Optical Networking Technology that uses Light Emitting Diodes (LEDs) for Transmission of Data. Li-Fi refers to Visible Light Communication (VLC) Technology that uses as Medium to Deliver High-Speed Communication in a Manner Similar to Wi-Fi. Li-Fi Provides Better Bandwidth, Efficiency, Availability and Security than Wi-Fi and has already Achieved High Speeds in the Lab. In this paper, we will give a Detailed Study on Li-Fi Technology, Its advantages, and Its Future Scope.