Intracellular parasites are microparasites that are capable of growing and reproducing inside the cells of a host.
Obligate intracellular parasites, on the other hand, need a host cell to live and reproduce.
[2] Facultative intracellular parasites are capable of living and reproducing either inside or outside cells.
[citation needed] The majority of intracellular parasites must keep host cells alive as long as possible while they are reproducing and growing.
Self-degradation of host proteins into amino acids provides the parasite with its primary carbon and energy source.