IP addresses. Explained.

this is you this is your computer and

this is you watching what is an IP

address IP addresses represent where you

live on the Internet and are needed to

send messages to computers outside of

your network imagine when you send a

letter to your great aren't you

you put her address on the front of the

envelope and the return address on the

back you send the message and expect to

get a reply this is what is going on

with your computer right now as you're

watching this except the destination

address of the thousands of messages

you're sending every minute is some

YouTube server and the return or source

address is the computer in front of you

just like with house addresses you won't

find two computers connected to the

internet with the same address somewhat

differently though computers don't use

geographical addresses but rather use a

string of numbers called an IP address

these IP addresses are how the device is

involved in passing the message know who

is sending what to whom not including a

source IP when sending a message over

the Internet would be like sending a

letter with no return address to a

complete stranger who has to deal with

billions of letters every minute and

expect to get a reply yeah good luck

with that

so quick recap IP addresses are unique

series of numbers which identify

computers on the Internet one to watch

YouTube you need an IP address want to

send an email you need an IP address

want to browse gifts of adorable cats

you need an IP address cool moving

swiftly on if you look at an IP address

in a bit more detail you'll notice that

it's basically four numbers separated by

dots this particular IP address would be

pronounced using dot or

point between the numbers doesn't really

matter it's just personal preference as

mentioned in a previous video sending

information across the network will

eventually lead to ones and zeros being

transmitted in the form of electrical

signals an IP address has 32 of these

ones and zeros with a little bit of

arithmetic we can work out that there

are four billion two hundred and ninety

four million nine hundred and sixty

seven thousand two hundred and

ninety-six addresses available for use

on the internet wait hang on there are

seven billion people in the world about

three billion of whom are connected to

the Internet some of these people will

have multiple internet connected devices

the number of which is going up

literally every second are we running

out of addresses why yes we most

certainly are

the super amazing techy people realize

this problem back in the late 1990s and

hence came up with the system to slow

down the rate at which IP addresses were

being used up that is called NAT

imagine a postman standing at your front

door looking towards the house is like

looking at the devices on your home

network and looking out towards the road

is like looking out towards the Internet

the postman takes three letters one from

Alex watching YouTube one from David

sending an email and one from Jane

watching gifs of adorable cats

the postman sends off these letters and

any replies get given to him he then

comes back to the house with the replies

and gives them to Alex David and Jane

respectively same idea with NAT it takes

multiple addresses from inside your

network and presents a single IP address

pointing out towards the Internet thus

reducing the number of IP addresses used

this is why if you take a look at your

network settings at your house and then

ask a friend to do the same at theirs

it's likely you'll have incredibly

similar IP addresses NAT is working in

the background and so this is you this

is your computer and this is you

finishing what is an IP address