We begin chapter 3 of Maseches Makkos, which deals with all the halachos relating to lashes: which transgressions carry the penalty of lashes, and how the lashes are actually administered.
The Mishnah opens: "V'eilu hein halokin" - these are the ones who receive lashes. It should be emphasized that our Mishnah and those that follow list certain transgressions for which a person receives lashes, but this is by no means an exhaustive list. The Rambam counts two hundred and seven transgressions that carry lashes, and he gives a mnemonic for it: "ya'aku zar" (zar - a stranger), that lashes are given to a zar, and this serves as a sign for remembering the number two hundred and seven. The Mishnayos of our chapter list cases that contain a novel point or a special idea.
The first group - transgressions that carry kareis:
Even though these transgressions carry a punishment at the hands of Heaven, lashes are nevertheless administered for them by beis din, and these are they:
"Haba al achoso" - one who has forbidden relations with his sister.
"V'al achos aviv" - his father's sister.
"V'al achos imo" - his mother's sister.
"V'al achos ishto" - his wife's sister.
"V'al eishes achiv" - his brother's wife.
"V'al eishes achi aviv" - the wife of his father's brother.
"V'al hanidah" - his own wife, while she is in a state of niddah.
The second group - prohibitions of lineage that do not carry kareis:
Here the Mishnah lists cases that do not carry kareis but are prohibitions of lineage: women whom a kohen may not marry, and also women whom even a Yisrael may not marry.
"Almanah l'kohen gadol" - a widow, a woman whose husband has died, is forbidden to a Kohen Gadol, and he receives lashes for her.
"Gerushah vachalutzah l'kohen hedyot" - a divorcee, a woman who has been divorced, or a chalutzah, a woman who underwent chalitzah, to an ordinary kohen. A chalutzah is generally understood to be a rabbinic prohibition, and even so the person receives makkas mardus, which is a rabbinic form of lashes and not the standard lashes.
"Mamzeres unesinah l'Yisrael" - a mamzeres, who comes from forbidden relations; and a nesinah, who comes from a group of people who were accepted by the Jewish people as converts without it being recognized that they were from the seven Canaanite nations who had to be destroyed, and one may not marry them because of the Torah's prohibition of "lo sischatein bam."
And the reverse - a Jewish woman who marries a nasin or a mamzer.
A woman who carries two prohibitions:
A woman who is both a widow and a divorcee, who marries a Kohen Gadol who is forbidden in both - he is liable to two sets of lashes for her, since she is forbidden to him as a widow, and she is also forbidden to him as a divorcee, a prohibition that applies even to an ordinary kohen. This scenario is speaking of a case where she first became a widow and only afterward became a divorcee, for otherwise there is the problem of "a prohibition does not take effect upon an existing prohibition." But when she was first a widow and only afterward became a divorcee, since the second prohibition is one that affects a larger number of people - not only a Kohen Gadol but even an ordinary kohen - it takes effect on account of the other prohibitions that exist there, and therefore it also takes effect regarding the Kohen Gadol, and he is liable for both.
In contrast, the Mishnah continues: a woman who is both a divorcee and a chalutzah - he receives lashes for only one. For as was mentioned, the additional lashes are given because of the chalutzah's resemblance to a divorcee, so it turns out that we have nothing here but a divorcee twice over, and her prohibition is not more severe. Therefore he receives lashes only for her being a divorcee.
In summary: in this Mishnah we listed those who receive lashes - first the arayos that carry kareis, and even so beis din administers lashes for them; and afterward the prohibitions of lineage that do not carry kareis: a widow to a Kohen Gadol, a divorcee and a chalutzah to an ordinary kohen, a mamzeres and a nesinah to a Yisrael, and a Jewish woman to a nasin or a mamzer. We also learned the law of a woman who is both a widow and a divorcee, for whom he is liable to two sets of lashes, as opposed to a divorcee and chalutzah, for whom he receives only one.