What is Li-Fi?
Li-Fi stands for Light Fidelity is a Visible Light Communications (VLC) system running wireless communications travelling at very high speeds. While Wi-Fi uses radio waves, Li-Fi runs on visible light. This means that it accommodates a photo-detector to receive light signals and a signal processing element to convert the data into 'stream-able' content.
An LED lightbulb is a semi-conductor light source meaning that the constant current of electricity supplied to an LED lightbulb can be dipped and dimmed, up and down at extremely high speeds, without being visible to the human eye.​ That what make Wi-Fi speed of up to 224 gigabits per second. The obstacle that faces scientist now is that Li-Fi signals cannot pass through walls, so in order to enjoy full connectivity, capable LED bulbs will need to be placed throughout the home which requires the lightbulb to be on at all times to provide connectivity day and night.
Researcher at ​Eindhoven University of Technology are developing a Wi-Fi network with a speed of 42.8 GB per second 200 terahertz (THz) per second depending on infrared rays. Compare it with Wi-Fi 5 MGz. The head project at the university declared that the amazing new technology will be available in 5 years.