Transgender is the term for anyone who doesn't fit into societies expectations for gender. That means crossdressers, gender queer, gender fluid, butch woman, tomboys etc.
Transsexual, is the word for someone with an actual birth defect: being born in the wrong body. Hormones in the womb programmed that brain of the fetus, to laterally be, the opposite sex.
There can be male to female transsexual people, or transwomen. Or female to male, transmen.
You are referring to transwomen. There are some straight men who cross dress, an they identify as men an are perfectly happy being men, the same for drag queens, who are usually gay male performers. They also have secure male gender identity's (or their brain sex matches their body) they are Transgender. And should Not, be mistaken for Transsexual women. Or transwomen, who have male bodies, and are neurologically female.
Transwomen can have hormone replacement therapy, or estrogen to feminize them, and this produces breast growth. The can get implants, facial feminization surgery, and of course down there. Contrary to popular belief, the penis is not cut off, but inverted, and formed into a functional, biological replica of any other woman. Of course, a transwoman started with a male body, so she will not be ale to have children, or get periods.
It's always nice to see people who want to be educated and informed.