The full name of Li-Fi is Light-Fidelity. Li-Fi's inventor is Professor Harald Haas. In 2011, he released the first of the Li-Fi originators. And he showed how you can communicate with the help of lights.
However, since then, he has been doing extensive research on Li-Fi, and he was tested for Li-Fi three weeks earlier. And the Li-Fi in the examination is much faster than Wi-Fi. 
Actually work on the concept of Li-Fi (VLC - "Visible Light Communication"). Now if you do not know what VLC is? Then try to explain. If you give an LED bulb to Constant Input Power, you will see its Output and Constant. If you make some changes to Input Power, you will see the output change, with this idea you can create a kind of communication system. So Wi-Fi communication will replace with Li-Fi in future.