Light, which consists of massless particles called photons, travels at the speed of light in a vacuum, denoted by the symbol "c." In the theory of relativity, this speed is considered a fundamental constant of nature and is approximately 299,792 kilometers per second (about 186,282 miles per second).
According to the principles of relativity, light attains its full speed of approximately 299,792 kilometers per second immediately upon its emission. From the moment light is generated, it propagates at this constant speed without needing any acceleration or adjustment period.
It's important to note that the speed of light in a vacuum is the maximum speed at which information or signals can travel in the universe. No matter how much energy is applied to an object with mass, it cannot reach or exceed the speed of light. This characteristic is a fundamental aspect of our understanding of the laws of physics.