The speed of light in a vacuum is approximately 299,792 kilometers per second (or about 186,282 miles per second). This speed is considered a fundamental constant of nature and is denoted by the letter "c" in scientific equations. It plays a crucial role in the theory of relativity, which was developed by Albert Einstein. Light travels at this incredible speed, allowing it to cover vast distances in space quickly. For example, it takes about 8 minutes and 20 seconds for light from the Sun to reach the Earth. Understanding the speed of light helps scientists explore the universe and comprehend the behavior of light and other electromagnetic waves.