Depends. If a girl stares at you, and when you look at her, she shyly or quickly looks away, that means she likes you :)
If she’s giving you a dirty look (not that way, as in the evil eye) she hates you
If she licks her lips and winks while looking at you, run run, as fast as you can.
If she’s giggling with her friends and staring at you, someone in her friend group or her likes you :D (Credit to NarfyBarfy)