Some definitions:
Sex - either of the two main categories (male and female) into which humans and many other living things are divided on the basis of their reproductive functions.
Gender - the state of being male or female (typically used with reference to social and cultural differences rather than biological ones).
Sexuality - a person's sexual orientation or preference.
Queer - denoting or relating to a sexual or gender identity that does not correspond to established ideas of sexuality and gender, especially heterosexual norms.
