What is the Internet?

An attempt to break it down for a Grade 4 class

NO MORE BARRIERS

• We live in a time where the Internet is present everywhere around the world from the base camp of Mount Everest, and spanning across every continent

But what is it?

You’re already PART of it

• Since you’re close to 10 years, you’ve been surrounded by the Internet for all your life. (Does it tingle?)

Internet = Ice Cream Sandwich

Let’s start with “network”

• What does “network” mean to you?• You are in many “people” networks already:– your friends– your family– your school and community– people who love Spongebob

And a computer network?

• Similar to a "people network", a computer network is a group of machines that talk to each other.

• Just like your different kinds of "people networks", a computer network on the internet is hooked up to other computer networks which form a giant "web"

How does a website work?

• What happens when you type www.google.com in your web browser?

..making a phone call

• Every machine on the internet is given an address made of numbers to make sure every location is unique

• Why is that important?

machine talk

• The computers find each other with these address numbers

• Numbers are consistent across almost every speaking language – a German “1” is written no differently than a French “1”

But people speak words

• People finding a machine don’t want to speak in numbers

• We want to use words and / or names

Domain Name Service

• Imagine a giant phonebook (aka. Santa’s list?)• The phonebook can find every machine on the

internet through both their name and their number

• Eg. “google.com” = 74.125.226.112

How do machines TALK?!

• We understand that machines use the phone book to find each other…but then what?

• Ideas?

Idea #1

• Do machines talk in a human language? (like english for example)

• -it’s much easier for us to understand what is happening on the surface

• -but not every person speaks english and even within english are many dialects / ways of speaking

• -the internet is not free – size of your message determines its cost; like the post office

Idea #2

• If not a speaking language, then what?• Data• Every machine understands binary which only

allows 1’s and 0’s• MAAAAAAAATTHHHHHHH

Interruption everywhere

• Computer networks are not reliable and imperfect

• (REMEMBER THE WEB)• Just like a room full of people, machines can

also be interrupted during a conversation with another machine

• What’s the dealio?

We need PROTOCOL

• A protocol establishes rules for doing things• There’s a protocol for asking your teacher a

question• There’s a protocol for talking to your parents• There’s a protocol for addressing her Majesty,

the Queen of England and it doesn’t start with “yo Queen”

Chocolate layer = TCP

• TCP is the lowest level protocol of the web

Message example

• Imagine moving a large message from your room to your friends house

• Too big to bring in one piece• Too heavy to bring in one piece• Let’s break it down into a jigsaw puzzle; we

can then bring the smaller pieces over to our friends house and put them back together

• Problems?

Problem #1: order

• Order is kind of important• Impossible to reassemble the jigsaw puzzle

without knowing the order

Idea – tagging

• If order is important, then maybe tagging can help

• Before we break the puzzle apart, we can tag each piece so that we know how to put everything back

Problem #2 – data loss

• What if we lose a piece along the way?• A lost piece means we won’t have the whole

puzzle• I forgot to mention your friend lives on the

other side of the world – oops!• Ideas?

Idea - resend

• When your friend is ready, you bring over a small number of pieces

• Once they are safe, your friend tells you to send the next small batch

• If your friend is missing a piece, you have to re-deliver that whole batch

Tip of the iceberg

• I left out a LOT of stuff• I gave you enough words ; go google!

Questions?

• Erik Yuzwa of Wazoo Enterprises Inc.• http://www.wazooinc.com