What types of hair - and whose hair - are included in mourning-related hair-cutting prohibitions?

When there are hair-cutting prohibitions (or restrictions) for mourning-related practices, what types of hair are included? Is it just hair on the top of one's head and/or facial hair? Do the restrictions apply equally to men and women?* Do any leniencies that might apply in certain situations apply equally to men and women? Do those same leniencies apply to all hair types that are included in the restrictions?

*The reason I ask about both men and women in this question, is that men and women may have different types of hair and/or different types of hair that one cares about grooming (e.g., facial hair on men, "נימא" on women, etc.).