Sexual attraction/orientation has to do with who you like physically. Be aware that some people may be asexual, meaning to experience no sexual attraction. Other people may be heterosexual, homosexual, bisexual, pansexual, etc.. There is a difference between pansexuality and bisexuality, and we will discuss that shortly
Romantic attraction/orientation has to do with who you like emotionally. Like sexual orientation, someone may identify as heteroromantic, homoromantic, panromantic, biromantic, aromantic, etc.. Some people also identify as polyamorous, which speaks to a persons ability to have multiple romantic relationships simultaneously. This is not necessarily the same thing as when couples agree on open relationships that allow for additional physical relationships.
Sex is assigned at birth and biological. It is your genitals. This generally refers to the male and female sex (“male” as defined by a penis and “female” as defined by a vagina), though assignments are not limited to that. Intersexed individuals are often undermined in this respect. People who are intersex are born in a body that is not 100% biologically female or male (for example, with the presence of both male and female genitalia, or with internal sexual reproductive organs that do not match the sex of the external genitalia). Transgender individuals who choose to transition medically through sex reassignment surgery or hormone replacement therapy are not intersex.
Gender is not sex. Gender is how an individual identifies. If someone’s sex matches with their gender, as is true for the majority of the population, then they are cisgendered. People may also be transgender, meaning that they were either born with female sex characteristics but identify as male (FTM: Female to Male) or were born with male sex characteristics but identify as female (MTF: Male to Female). Not all people who identify as transgender choose to medically transition. Other people may identify at some other point on the genderqueer spectrum, for example as agender or bigender.
The vast majority of society conforms around the gender binary system. Binary refers to two, and the gender binary, as thus expected, states that there are only two genders. This is not true. In reality, gender is much more complex, multiple, and fluid. Queer theory shows gender as something that is not restricted solely to male and female, but rather as a spectrum. The “gender doughnut” does a decent job at depicting this more complex and comprehensive understanding of gender.
This is only the beginning to a vast and diverse topic. There is much more to understand about sexuality, gender, identity, expression, and the controversy surrounding all of it. I encourage everyone to educate themselves and to remain aware. If at any time you have further questions about anything like this, feel free to hit me up in my ask box at woofes.tumblr.com.