* Constant Speed: Light travels at a constant speed in a vacuum, approximately 299,792 kilometers per second (km/s). This speed is often rounded to 300,000 km/s for simplicity.

* Acceleration Definition: Acceleration is the rate of change of velocity. Velocity includes both speed and direction.

* Light's Straight Path: Light travels in a straight line, meaning its direction doesn't change. Since both speed and direction are constant, light does not accelerate.

Important Note: While light travels at a constant speed in a vacuum, its speed can change when it passes through different mediums, like water or glass. This change in speed can cause the light to bend (refraction). However, even when light bends, it doesn't experience acceleration in the traditional sense because its speed is still constant within that medium.