internships and fellowships

i'm getting a little confused with the after medical school process. i thought after medical school you go into residencies and work for 80 hours a week for low pay for about 4 years. i'm down with that. however, do you have to do hospital internships after medical school and before residency? and then you go to fellowship after your residency is over? can someone please shed some light on this subject? thanks

the sequence is med school -> internship (1 year) -> residency -> fellowship

however fellowships are not compulsory (except to complete certain specialisations) and the internship years is frequently just year 1 of your residency in reality, though some residencies still have them as seperate.