What is the difference between sex and gender?

In my opinion, I think that sex is more of a male or female thing while gender refers to more of a feminine or masculine sorta thing

Sex is your biological junk. Your reproductive organs; male, female. Gender is what you identify with (Bigender, cis, gender-fluid, and many more.)

sex is penis or vagina, gender is woman or man, you can have a penis but be a woman, because thats how you feel

Sex is your physical reality. Being female or male or intersex! Gender on the other hand, is defined entirely by society, it's a personal experience that goes further than the clothes you wear. Most people see gender through secondary sex characteristics (i.e the subtle differences between the sexes that can be changed more easily!) and for some, presentation (i.e clothes, hair.)

The difference between sex an gender is really quite simple from my understanding. Sex refers to biological means (what's 'down there'), where as gender refers more to social and cultural differences instead of biological ones. Gender and sex tend to be very loosely tied together though.

Sex has to do with your biological structure (chromosomes, hormone balances, etc.), while gender is more so an identity. Sex isn't made up, gender is (it's a man-made concept). Basically, sex is physical, gender is mental.

I think sex is your biological gender as in male, female where as gender refers to your femininity and masculinity.

Sex is biology, it is what genitals you were born with. Gender is what you identify as. The similar answer is that you were born with your sex and you chose your gender.

Sex generally refers to the biological sex assigned to you at birth - i.e. it's a boy! or it's a girl! intersex individuals also exist, but are less commonly talked about. Gender generally refers to the gender that you identify with or the "sex" that you identify with. Some people feel strongly that they are a girl or a boy, and some people don't strongly identify with either. Some useful terms: cisgender - your assigned sex and gender match (ex: a person born as a boy feels that he is a boy) transgender - your assigned sex and gender do not match (ex: a person born as a girl feel that he is a boy) genderfluid - your gender fluctuates from day to day, week to week, etc. Your gender can alternate between being genderless and being a boy and being a girl. This depends on the person agender - you feel as though you are genderless. This can be hard to explain and understand unless you've had the feeling before These terms of course are not exhaustive. Good luck!

Sex refers basically to your body's anatomy and characteristics, while gender is used to suggest one's own internal identity which could or could not match external appearance.