For example, my computer displays a list of wifi network in range, even it doesn't connect to any of them.
I don't know wifi protocol so I don't know whether my computer must actively send information out, e.g. handshake, ack..., in order to get the information of the networks, or it only listens passively?
If it sends information out, can others know about my computer and attack it even if I don't connect to any of those networks?
The question is not only applied to wifi but any other type of wireless connection.