Assigned (Female/Male) at Birth (AFAB or AMAB): This term refers to how babies are assigned as "female" or "male" at the time of birth based on the outward appearance of their genitals. It is not dependent on chromosomal sex.

In cases of intersex babies with ambiguous external genitals, considerations such as

• Data of adults with similar chromosomal variations and what gender they identify with as adults
• Potential surgical correction options (which is something that the intersex community is largely not in favor of because of the lack of consent they are able to give about surgical changes to their genitals when they are infants)
• Responsiveness to androgen
• Reproductive potential
• Familial input
• Imagined sexual activity
• Cancer risk

all weigh into the equation. Some states are now offering birth certificates to have a third gender option that is neither male for female, but that is not yet common practice.

Some people with intersex body variations (1-2% have intersex body variations) might have XX chromosomes and still be assigned "male" at birth (and vice versa) while others may have even been surgical assigned (a practice that we hope ends) when their genitals were ambiguous.

What's also important to understand here is that gender is both our innate sense of who we are and also a set of societally agreed upon set of appearances and behaviors that create a false binary. Therefore, assigning gender based on genitals can be incorrect and it can have very challenging (and even fatal) outcomes for the intersex and transgender people in which they do not necessarily align. 

Genitals: (the nerdy explanation) The phenotypical, physiological characteristics that are created during development by the chromosomal code that a body has for the reproductive system. (the easier explanation) The external and internal sex organs. The genitals can have variations beyond binary (M/F) that are either present from chromosomal creation, injury, surgery, and natural variation.   

The chart below shows a not-all-inclusive (and obviously imperfect) table that was an attempt I made back when I started teaching about this stuff several years ago. It shows the names of different types of hormonal changes, surgical changes, and congenital variations that all represent the variety of genitals that exist. 

Vulva: The external genitals that are typical with XX development. Vulvas can also be surgically created when needed. The vulva consists of the outer and inner labia, the clitoris, the vestibule, the urethra, and the vaginal opening. The vulva is not inherently "female" anatomy (because anatomy doesn't have gender). Commonly referenced as "the vagina", that's a eye-twitching inaccuracy for those of us in sexual health. 

Vagina: The vagina is the canal that generally goes from the opening that is part of the vulva to the cervix/uterus. However, after a hysterectomy, when created with a vaginoplasty, or in some intersex variations, a vagina might terminate in a closed cuff without a cervix or uterus. 

Front Hole: "Vagina" tends to be a very gendered term (i.e. "Boys have a penis and girls have a vagina"), so for those that have genitals that don't align with their assigned gender well use words that feel better. "Front hole" is a more neutral term for "vagina". Another term might be "anterior opening". Medical professionals might think "Front hole? Shouldn't that be the urethra"... and this is a thing that medical professionals can just get over. 

Clitoris: The clitoris is the typical formation of the genital erectile tissue in someone with XX chromosomes in the absence of an intersex variation. The clitoris and the penis are analagous and are formed from the same tissue during embryological development. (see the image below)

It is highly innervated and the glans of the clitoris sits at the top (belly end) of the vulva while the legs (crura) of it extend internally deep to the labia. The clitoris can be various sizes.

Testosterone can increase the size of the clitoris. People for whom XX anatomy doesn't align might have different names for their clitoris that are not as associated with women. The clitoris is the source of stimulation to orgasm in the majority of people who have a clitoris. 

The images below have various terms uses for similar parts. Some are more traditional medical terms and some are less "genderful" anatomy terms. 

Penis: The penis is the typical formation of the genital erectile tissue in someone with XY chromosomes in the absence of an intersex variation. The urethra typically (some intersex variations might have a penis with an opening at a different location) runs through the penis with an opening at the end in which urine and semen exit the body. The clitoris and the penis are analagous and are formed from the same tissue during embryological development. (see the image below)

The Pelvic Floor: A group of muscles with 3 layers (two of these layers are shown on the images below) that act have several functions:

• Supporting the abdominal and reproductive organs
• Urinary control
• Bowel Control
• Opening for sexual penetration and for childbirth
• Sexual control, comfort, and pleasure

The pelvic floor muscles are very similar in all types of genitals. The two figures shown below demonstrate the primary differentiation in their relationship to the penis, the clitoris, and the vagina.  

Same parts but arranged differently through embryological development: 
Below is an image I created to show a view of where the clitoral tissue goes (since most of the images created make it look like the penis gets large and the clitoris gets smaller. They are really not viewed from the right planes. Here's my attempt to be a little more thorough with the structures.