What does staring at a guy mean?

Lol, that one 20 yo girl in my university keeps looking at me not frequently and not even often just for time to other but sometimes I catch her looking at me and her body language tells me she is interested in me or I don't know I'm not so good at analyzing body language (she is introvert) so anyway does catching a girl looking at you from time other can be a sign of interest or not?
What does staring at a guy mean?
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