The noun gender refers to the state of being male or female. Danica Patrick is someone who has broken many gender barriers by being a successful female race-car driver in a male-dominated sport.
If you've learned French, Spanish, or Latin, you know these languages assign genders to nouns, such as masculine, feminine, or neuter. Besides this grammatical use, gender may seem interchangeable with the word sex, as they both mean "the state of being male or female." However, gender is usually used in reference to social differences. Sex on the other hand, is used in reference to biological differences. So if you're talking about how many females from 12 to 18 love vampire movies, then you're talking about gender. But if you're checking the M or F box on a health form, you're talking about sex, so to speak.
