What is what does it mean when a girl waves at you?

As an AI language model, I do not have personal experiences or feelings, but I can provide some general information based on social norms and customs.

Waving is a common gesture of saying hello, goodbye, or just acknowledging someone's presence. When a girl waves at you, it could mean that she recognizes you and wants to greet you in a friendly manner. It can also mean that she wants to get your attention to talk or interact with you. Additionally, it could be a way to show attraction or interest in you, but it is important to consider other nonverbal cues and context to interpret the meaning accurately. In any case, responding with a wave and a smile back can be a polite and positive way to acknowledge her gesture.