There are many sexualities.
When you are attracted to the opposite gender.
When you are attracted to the same gender. Lesbian refers to a homosexual woman, while gay can refer to both gender binaries.
When you are attracted to 2 genders, most commonly both men and women.
When your attraction is regardless of someone’s gender. Such as transgender, non binary, etc...
When don’t experience any sexual attraction.
These are all real sexualities. People who say that pansexual is just another word for bisexual or that if you’re asexual you’re just a late bloomer are just plain wrong. That’s like saying the sun isn’t real.