Here's why:

* Size: The Sun is a star, and it's incredibly massive. It has a diameter of about 865,000 miles (1.4 million kilometers). The Moon, on the other hand, is a relatively small natural satellite with a diameter of only 2,159 miles (3,474 kilometers).

* Distance: Even though the Sun is much larger than the Moon, it appears smaller in the sky because it's much farther away from Earth. The Sun is about 93 million miles (150 million kilometers) away, while the Moon is only about 238,900 miles (384,400 kilometers) away.

So, although the Moon appears larger in our sky, the Sun is vastly larger in actual size.