Parts of Identity

Identity is something that everyone thinks they understand, and most people don't give a second thought to. Male, female, gay, straight, these words are recognized as parts of a person's identity. However, there are many other possible identifications that these words cannot portray. What do you call someone who has female parts, but expresses herself as a man? Or someone who doesn't want sex, but still wants a relationship? Plus, all these various parts can be scrambled each and every way until four words has absolutely no chance at describing it.

There are four main parts of a person's identity: Gender Identity, Gender Expression, Biological Sex, and Attraction. One of the best images I've found to show these parts of identity is the Genderbread Person. Unfortunately, this image does not explain what the various scales mean.

Gender Identity is a person's inner identification of being a certain gender. To explain this better, think of two maps that the brain has of your body: there is the "physical" map, which is what your eyes see when you look down at your body, and your "mental" map, your brain's idea of what should and shouldn't be a part of the body, and where everything should be. For example, your mental map shows you should have two arms, two legs, and so on, and your physical map matches. Gender Identity is part of the mental map of your body, telling you what gendered body you should have.

For example, here is a person named Tim. Tim was born male, so his physical map is a male body. However, his mental map shows him as a woman.

Gender Expression is what gender a person represents with their words and actions. This identification is heavily dependent on current social gender stereotypes, such as "only girls can wear skirts." For example, a physically female person who goes by a male name and wishes to be referred to by male pronouns has a "masculine" gender expression, despite the fact that the person still has female genitalia.

Tim, accepting that he does not feel male, takes up the female name Tina, and starts representing herself as a female.

Biological Sex is a person's physical body and its construction in terms of gender representation. This is not as simple as "male" and "female," however; someone can have a female chest with male genitalia, a male chest with female genitalia, or no genitalia at all. 

Tina later gets surgery to get breasts to better represent herself as a female, but does not yet change her male genitals. 

Attraction is the only part of the original Genderbread person I had a problem with. While the poster shows only one scale, there are actually two. Every person has four types of relationships with the people around them: familial (family), platonic (friends), romantic (SO), and sexual (sexual partner). Notice how "romantic" and "sexual" are not the same thing. This is what confuses people most about attraction. The difference is described as such:

Romantic Attraction is a feeling of emotional attraction towards other individuals. This is not a sexual desire for that person, but an emotional one; a desire to get to know that person better, to spend time with them, to deeply understand them and make them happy. 

Sexual Attraction is a feeling of physical attraction towards other individuals. This is separate from romantic desire because it is very focused on the body and its form, creating desire to be close to the body, to feel skin on skin, see it, taste it, and so on.

Another potentially confusing part of attraction is libido, or sex drive. A person's sex drive does not affect their romantic or sexual attraction; someone may be very attracted to people and have a low sex drive, or not attracted to anyone and have a high sex drive. 
Most people have a matching set of romantic and sexual attractions. For example, a traditional straight person is, in long terms, a heteroromantic heterosexual. There are some cases where they do not match, however. For example, a homoromantic bisexual desires romantic relations with the same sex, but feels sexual desire for both sexes.