Computer Networking Tutorial by Bucky (from Youtube)

Computer Networking Tutorial - 1 - Introduction to Networking 

Computer Networking Tutorial - 2 - Networking Basics

Computer Networking Tutorial - 3 - Network Topology 

Bus, ring, star and mesh topologies explained.

Computer Networking Tutorial - 4 - OSI Model Physical Layer

Overview of the 7 layers of OSI (Open Systems Interconnection)

Taken from www.WindowsNetworking.com

Physical and Data Link Layers- transmit data, transmit frames and packets
Network, Transport and Session Layers- communicate between different computers
Presentation and Application Layers- present the data to you (your software like the browser), data formatting


The Physical Layer comes with things like cables, fiber optics, radio waves, etc. It also has your network connectors and network topology. (The layer of stuffs that you can see.)

The difference between analog and digital signals (used to send data between two computers) is also explained in this video.

Computer Networking Tutorial - 5 - OSI Model Data Link Layer
 
What the Data Link Layer does is take the data (bits/binary code) and formats it into a frame, a unit of data that contains your address information. (It puts the bunch of binary code, together with the address of the sender and the address of the receiver, in an envelop [the frame]).

Computer Networking Tutorial - 6 - OSI Model Network and Transport Layer


The job of the Network Layer is to control the passage of packets along routs in the network. A packet is a unit of data that is formatted to send it a signal over the network.. The Network Layer gathers information from different parts of your networks (like computers...), called discovery, and that's how it finds the quickest path.


The main job of the Transport Layer is to ensure that the data is sent and received in the same order.