what does intersex mean?

A person born with both sets of genitals, not always fully formed.

Possessing anatomical and/or physiological characteristics over the life span which are markedly atypical for either female or male phenotypes or genotypes.

Intersex people are a rare phenomenon where someone happens to have both male and female genitals in some way. They only make up about 1% of the human population and are the only people who can get a complete sex change. Depending on how rich their parents are, this is often done shortly after they are born with parental consent. Intersex people also only receive a sex change if they want it, and after their doctor studies their chromosomes/DNA to determine which sex will best fit. 

Maybe this will help:

https://www.youtube.com/watch?v=n_5l2fwWGco

Intersex people are individuals born with any of several variations in sex characteristics including chromosomes, gonads, sex hormones or genitals that, according to the UN Office of the High Commissioner for Human Rights, "do not fit the typical definitions for male or female bodies". This is the flag

Individuals born with any of several variations in sex characteristics including chromosomes, gonads, sex hormones or genitals that "do not fit the typical definitions for male or female bodies"