What is the difference between the terms sex and gender?

In the English language, these terms tend to be used interchangeably. There is little difference in how they are used. Either refers to the male or female. There is, however, according to the rules of the English langauge, a difference in how they SHOULD be used. The term "gender" is used in English grammar to indicate a classification between the male and the female or people, animals, and other living beings.For example, the pronoun of "he" is used to describe a male gendered animal, while "she" would be used in female gendered animals. We may ask someone what sex they are. We classify animals by their sex, but politely classify human beings by their gender.Simply put, it is more appropriate and polite to ask a person to indicate their gender, rather than their sex.

 Sex is more often used in its verb form to denote an action undertaken by animals of both genders.