Dating vs Relationship

I don't understand how dating works. Like, dating and being in a relationship are completely different but ..do people still ask to make it official or does it just happen. My boy got me a pedicure for Vday and the woman catering to me, she was asking him, "Is this your girlfriend?" And he confirms it and I'm like. This is the first i'm hearing of it - I'm not mad cause I was curious of where that status was but I always wondered if he'd ask me to take that step with him. I dunno, it sounds so stupid but he would be my first boyfriend (And I'm 21), so it's just what i would have.. imagined happening, i dunno how this works 😅