Having multiple orgasms means having more than one orgasm within the same lovemaking session.
Although multiple orgasms are possible for both men and women, they happen primarily among women.
Unlike men, most women do not go through a post-sex refractory period (a time when the body cannot achieve orgasm), and therefore many women, if properly stimulated, can have several orgasms in a row.
Unfortunately, after the first orgasm the clitoris often becomes too sensitive to be stimulated again, and therefore further orgasms become hard to achieve.
A minority of men can have multiple orgasms, usually because they have a very short refractory period.
Despite that, even the luckiest of men rarely manage to go beyond a second or third orgasm, while lots of women have the ability to pass that number.