Gender previously was refered to as the nonpysiological aspects of being female or male - the cultural expectations for femininity or masculinity.
Today, gender is used to discuss male-female differences that may be caused by any combination of environment and biology. Also, it is used as a label for the system of expectations held by societies with respect for feminine and masculine roles.
It is only appropriate to disclose the definition for sex, as it pertains to gender, in order to allow an indiviudal to grasp the full meaning of gender. Hence, sex used to refer to a person's biological maleness or femaleness. Today, sex encompasses and is rather reserved for discussions of anatomy, as well as the classification of indiviudals based on their anatomical category.
What is more, gender and sex together, as well as their stereotypes are an intriguing topic, which is further evaluated at the following link: SexandGender.