What's the difference between a prokaryote and a eukaryote?

Prokaryotes tend to be single-celled organisms, such as bacteria, and eukaryotes are multicellular organisms like plants, animals and funghi. The two domains are also different at the cellular level, too. Prokaryotes have no nucleus and their DNA is circular, whereas eukaryotic DNA is arranged into chromosomes and packed into a nucleus. Prokaryotes have smaller ribosomes than eukaryotes, a cell wall (eukaryotes do not), and they may also have a flagella or additional DNA in plasmids.