You've asked a very good question, but it touches on a subject that is quite complex, and so it is not easy to answer.
Einstein was the first to notice that the speed of light appears to be a very unique characteristic of our universe. Matter can never travel as fast as light, and the speed of light in a vacuum is constant. But not only is the speed of light constant, it is constant for ANY observer, no matter what their speed is. But this is only true for this one speed- the speed of light.
That means that if you are driving at 99% of the speed of light and you turn on your headlights, you could measure that they shine forwards AND backwards at 186,000 miles per second. and not only that, but I, here on Earth, would measure your headlight beams as traveling at 186,000 mile per second too!
It makes no sense to our conventional minds. The way it works is that time itself turns out to be a variable when relative speeds are near to the speed of lightt, The rate at which time passes actually changes. We can observe that particles with precisely known radioactive decay rates - muons for example - decay more slowly when they are moving at near lightspeed.
Special Relativity is a huge and advanced topic, and leads into the still more advanced and more complicated General Relativity, where things are even more, well, unfamiliar. It is VERY unlikely that you will be prepared to understand the mathematical details of these themes, but if you search the web, you should be able to find explanations that you can begin to make some sense of. I would strongly suggest that Yahoo answers is not the place to reliably explore this further.