Here's why:

* DNA but no nucleus: Prokaryotic cells have their DNA located in a region called the nucleoid, which is not enclosed by a membrane.

* Lack of membrane-bound organelles: Prokaryotes lack the complex internal compartments (organelles) found in eukaryotic cells, such as mitochondria, Golgi apparatus, and endoplasmic reticulum.

Examples of prokaryotes include bacteria and archaea.