Really, it is so vague. Literally any casual relationship can be termed as a boyfriend. I have observed that it is a trend to use this term by women nowadays to cover up any relationship they have. They are using it as a newly found freedom and to avoid slutshaming. You want to fuck that guy? Just make him your boyfriend and fuck as much as you want with no consequences! Just break up later. It is basically a combination of friend, fuckboy and husband. There are elements of commitment but still casual or can even be sexless. She can be single with a boyfriend or have multiple boyfriends. I do not know why men obsess over cheating so much when she has had dozens of 'boyfriends' before you who she is very well granted to fuck with. So just when she is with you now does her past disappear? What if you are just one of those boyfriends? Does she have any pair bonding ability left? Will she not want to go back in the wild again?

I made a table to see where a boyfriend stands and it is ambigious as hell.

Is there? | Friendship | Commitment | Sex | Fuckbuddy | n | n | y | Simp | n | y | n | Friend | y | n | n | Husband | y | y | y | Boyfriend | y/n | y/n | y/n |