What are meteoroids ?

Explanation

**Step-by-Step Solution:**

1. **Definition of Meteoroids**: Meteoroids are small rocky or metallic bodies that exist in space. They are significantly smaller than asteroids and can vary in size from tiny grains to objects as large as a boulder.

2. **Location**: Meteoroids are found within our solar system and they typically revolve around the Sun, much like planets do.

3. **Entry into Earth's Atmosphere**: When a meteoroid enters the Earth’s atmosphere, it travels at high speeds. As it moves through the atmosphere, it encounters air resistance.

...