It sounds like it ought to protect you, but you’re not entirely sure how – or even if your computer has one!
That’s why you need to watch this short video. From about the 2:50 point, Gary Rosenzweig provides a generic explanation of firewalls, then explains how they differ depending on whether you use a Windows or Mac computer before returning to valuable cross-platform explanations.
It’s a worthwhile five minutes (eight if you watch from the beginning – do that if you have a Mac).
httpv://www.youtube.com/watch?v=fed7O1-pzVU