Here's why:

* Nebula Size: Nebulas are vast clouds of gas and dust, spanning light-years in diameter. Some of the largest known nebulas are hundreds or even thousands of light-years across.

* Star Size: Stars come in a variety of sizes, but even the largest stars are typically only a few million miles in diameter.

Think of it this way: a nebula is like a giant, sprawling city, while a star is like a building within that city. The city (nebula) is far larger than any single building (star) within it.

Example:

The Orion Nebula, a famous stellar nursery, is approximately 15 light-years across. This is many times larger than our own Sun, which has a diameter of about 865,000 miles.