How does a computer network enable communication between devices

Question

I am trying to understand how data is transmitted across a network and what key components enable communication. My questions are:

• What role do IP addresses, MAC addresses, and protocols (TCP/IP, UDP) play?
• How does data travel through network devices like routers, switches, and firewalls?
• How do client-server and peer-to-peer models impact communication?

A simple explanation or an example of a device communicating over a network would be helpful.