“How does HTTPS actually work? ….. How was data protected? How can a client and server create a secure connection if someone was already listening in on the wire? What is a security certificate and why do I need to pay someone to get one? …..”

This is a really good article that details how HTTPS works and its purpose and importance in web development.

How HTTPS Secures Connections: What Every Web Dev Should Know (blog.hartleybrody.com)