Here's why:

* Carbohydrates are defined as molecules composed of carbon, hydrogen, and oxygen, typically in a ratio of (CH2O)n.

* Polysaccharides are large, complex carbohydrates made up of many simple sugar (monosaccharide) units linked together by glycosidic bonds.

So, while polysaccharides are a more specific category, they are fundamentally carbohydrates.