They are essential for protein synthesis, and their structure is very similar in both types of cells. However, there are some key differences:

* Eukaryotic ribosomes are larger (80S) and have more proteins than prokaryotic ribosomes (70S).

* Prokaryotic ribosomes are smaller and are found in the cytoplasm, while eukaryotic ribosomes are found in the cytoplasm, the endoplasmic reticulum, and the mitochondria.

So, a ribosome itself isn't classified as either eukaryote or prokaryote. It is a cellular component found in both types of cells.