Welp *Cracks joints*
Prepare for a long explanation!
Persona is a kind of image or mask that you make when interacting with others, Such as being kind to your aunt or being polite to your teacher, Personas is quite similar to multiple personalities, However, You have full control over your persona, It's the image of you that everyone else sees and keeps the core self hidden, Personas, Like personalities, Can have their own age, gender and etc as well, It is purposely made as a sort of profile for you to use to be more comfortable with your surroundings.