Physical layer: represents the physical devices that interconnect computers
Data Link: Network Interface/Network access layer, Responsible for defining a common way of interpreting these signals so network devices can communicate
The Ethernet standards also define a protocol responsible for getting data to nodes on the same network or link.
Network 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 is the heart of the Internet and most smaller networks around the world.
Transport layer: Sorts out which client and server programs are supposed to get that data
Transmission Control Protocol (TCP) commonly called TCP/IP due to its usage together with IP. Ensure that data gets reliably delivered.
User Datagram Protocol (UDP)
Application layer: application specific HTTP (Hypertext Transport Protocol), SMTP (simple mail transport protocol)