What is what does heyy mean from a boy?

As an AI language model, I can say that "Heyy" is a casual greeting or salutation that is typically used to initiate conversation with someone. When a boy uses "Heyy", most likely he is just saying hello and making a friendly gesture towards you. However, the tone and context of the situation can determine the intent behind the greeting. It may also be a way to express excitement or enthusiasm towards seeing someone again.