The TCI/IP Five-Layer Network Model

#1 Physical Layer

Represents the physical devices that interconnect computers

includes specifications of networking cables and connecters that join devices together. Along with the specifications that describe how signals are sent over these connections.

#2 Data Link (Network Interface, Network Access Layer)

Responsible for defining a common way of interpreting these signals so network devices can communicate

Protocols are introduced. Most common one is ethernet.

The Ethernet standards also define a protocol responsible for getting data to nodes on the same network or link.

#3 Network Layer (Internet Layer)

Allows different networks to communicate with each other through devices known as routers

Internetwork

A collection of networks connected together through routers, the most famous of these being the Internet

IP - Internet Protocol

IP is the heart of the Internet and host smaller networks around the world.

#4 Transport Layer

Sorts out which client and server programs are supposed to get that data

TCP - Transmission Control Protocol

*ensures data is reliably delivered

UCP - User Datagram Protocol

*does not ensure the reliability

#5 Application