01. TCP_IP Protocol

The dominant protocol used is the TCP/IP protocol, consisting of:

1. Application: where user-facing applications operate.
   • Web browser (HTTP), email client (SMTP), DNS, etc.
2. Transport: manages the connection between two devices.
   • TCP (reliable, ordered delivery), UDP (fast, best-effort delivery).
3. Network: global addressing and routing using IP addresses to get a packet from the source network to the destination network.
4. Link: communication on the local network segment using MAC addresses to deliver a frame to a specific device on LAN.