size
extremely small vs larger
number of cells
unicellular vs multicellular
nucleus
no true nucleus vs nucleus bound by a nuclear envelope
organelles
no membrane-bound organelles vs many organelles bound by a double membrane (chloroplasts, nucleus, mitochondria) or a single membrane (vacuoles, endoplasmic reticulum, Golgi apparatus, lysosomes)
cell wall
peptidoglycan cell wall vs cellulose cell wall
DNA
circular DNA in cytoplasm vs linear DNA in nucleus