Differences between intracellular and extracellular digestion are
(i) Intracellular digestion, occurs inside the living cells with the help of lysosomal enzymes. Food particle is taken in through endocytosis. It forms a phagosome, which fuses with a lysosome. The digested material pass into the cytoplasm. The undigested matter is thrown out by exocytosis. It occurs in Amoeba, Paramecium, etc.
(ii) Extracellular digestion In case of coelenterates digestion occurs in gastrovascular cavity. This cavity has gland cells which secrete digestive enzymes over the food. The partially digested fragmented food particles are ingested by nutritive cells. It occurs in Hydra, Aurelia, etc.