Li-fi (Light Fidelity) is a method of transmitting data wirelessly using LED (light-emitting diode) technology. This technology has higher potential. It is very much possible to transmit the data via light by changing the flicker rate that gives different strings of 1 and 0, and its intensity is modulated so quickly that the human eyes cannot notice. Li-Fi has the advantage of being able to be used in sensitive areas such as in aircraft without causing interference. However, the light waves used cannot penetrate walls. In this technology the LED bulb will hold a micro-chip that will do the job of processing the data. The light intensity can be manipulated to send data by tiny changes in amplitude. This technology uses visible spectrum of light, a part of the electromagnetic spectrum that is still not greatly utilized. In fact the technology transfers thousands of streams of data simultaneously, in parallel, in higher speeds with the help of special modulation, using a unique signal processing technology. The light used to transmit the data is called D-light. Some applications of this technology are it can be used in the places where it is difficult to lay the optical fibre like hospitals. In operation theatre LiFi can be used for modern medical instruments. In traffic signals LiFi can be used which will communicate with the LED lights of the cars and accident numbers can be decreased. Thousand and millions of street lamps can be transferred to LiFi lamps to transfer data. In aircraft LiFi can be used for data transmission. It can be used in petroleum or chemical plants where other transmission or frequencies could be hazardous. And also there are four models available. Those are giga beam, giga dock, giga shower, giga mimo and giga spot. By this technology it is possible to achieve more than 10 Gbps that means theoretically, allowing a high definition film to be downloaded in 30 seconds. In future data for laptops, Smart phones, and tablets can be transmitted through the light in a room by using Li-Fi. If his technology can be put into practical use, every bulb can be used something like a Wi-Fi hotspot to transmit wireless data.