Ruthieie

Hi! I'm pretty inexperienced in picture editing...but here's what I'd like to do-- (I'm sure it has some name, and it's in tutorials, but I don't even know what to look for, lol) I'd like to take away the background of a picture, leaving only the subject in whiteness? Is this possible? Does it have a name, and could someone kindly point me in the right direction? Please? Thank you so much! Ruthie