Here is my entry:    "Hey Carl,     SO you want to understand the idea and concept of VLANs...let me simplify it for you.  Carl..you've traveled on an airplane before, right?  Of course you have, so what do you do?   You pick a destination, when you want to go, your seat assignment, and then purchase it.  Once purchased you get a ticket that has a Flight Number on it.   On the day of your trip, you go to the airport, go through security, look at your ticket, you check your flight number and see which Gate you need to be at.  Once at your Gate you see it's labeled with your destination and flight number, you wait for your plane, board and off you go.    So now that you understand that, let's peel back the label and let's reveal the players here:  The Airport would be the Switch in a network, The Gate would be the switchports that cables plug into, The airplane is the data that travels the Flight Number would be the VLAN   You see with out flight numbers (VLANs) we wouldn't know which airplane to hop on to travel, so it would utter chaos and people hopping on random planes, going to random, places.   So VLANs allow us to say "hey you belong on this plane to get to your destination, the Gate might change, but the Flight number won't" .       You think you got it Carl?  "    - Tony Cuevas   ... View more