I don’t know what those symbols mean, what is that in English?
learn. you ought to be capable.
That’s a smiley face (turn your head sideways and you will see the eyes and the mouth. More common use includes a dot.
In high-tech medium, the characters are translated into actual smiley-face symbols.
:), :-) — Smiles
:<, :-( — Sad
:-O — Surprise
Started in the usenet world. It’s not a “young girl” thing, it’s an old computer geek thing.