What is a network?
This is talk the type of tick tock.
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You learning about Kenay and then you also going to learn about hacking.
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Well done, poodle.
You've got a lot of learning to do.
So today we're going to learn about what is a network.
Now, if we're going to talk about networking, we should really define what a network is.
So what is a network now?
I'm not talking about a social media network.
I'm not talking about your contacts, let's say, on Facebook or LinkedIn or Twitter or tick tock or
whatever.
Your social media platform of choices we're not talking about is social media network.
In this case, we're talking about a computer network.
So what is a computer network?
And she has a challenge.
I'm going to ask the robots what a computer network is.
See how much you understand by this definition.
Alexa, what is a computer network?
A computer network is a digital telecommunications network for sharing resources between nodes, which
are computing devices that use a common telecommunications technology, data transmission between those
who supported over data links consisting of physical cable media such as twisted pair of fiber optic
cables, or by wireless methods such as Wi-Fi, microwave transmission or freespace optical communication.
OK, so there's the course we finish now.
We all understand what computer networking is.
Yeah, if only now, if you're a robot, you may be able to understand everything about computer networking
just by listening to those two paragraphs.
But I think for us, we need to spend quite a bit more time to really understand what a computer network
is and understand how computer networks work.
Let's start firstly with the why.
Why do we have computer networks?
What's the whole point of the Internet?
What's the whole point of all this infrastructure that's been built around the world?
And the big reason to have a network as per this definition is to share resources.
We want to share information or share some kind of resource with someone else.
Now, what is a resource?
In the old days, a common example of a resource would be a printer.
If you had an office with 100 people in the office, you could buy a printer for every workstation or
for every PC.
And that's what they had to do before the days of networking.
They either had to have a printer for every computer or have no printers, or what they had to do is
do something like this where they copy a file onto a floppy disk and then go over to the printing station
and then print it manually.
It's not cost effective to buy a printer for every workstation or for every person.
It makes much more sense to have a centralized resource, in this case a printing resource, and share
that resource amongst the people in the office.
So rather than having, let's say, 100 printers for 100 people only, let's say have 10 printers.
So you've reduced the cost by creating a shared resource, a resource that can be shared by what are
called clients.
So we have client devices or PCs in this example that are sharing a resource, in this case a printer.
Another example is file sharing.
This is very common.
I want to share a file with you.
So how do I do that now?
In the old days, the way to do that was to get a floppy disk like this.
The problem with these floppy disks is in the old days, they're only supported one point for four megabytes.
It's not a very big drive, but there you go.
Really old example.
So they'd have to if they wanted to share a photograph or a file with someone else that have to copy
it to this floppy disk, then walk using what we would call sneaker net.
So they'd firstly have to copy the photo or the file onto this disk, then walk using sneaker net across
the office, put it into the other computer and then access the file.
So that's how they would share a resource in this case, a file or a photograph.
Now, today, we still use this kind of technology by using USB thumb drives.
So if I wanted to share a resource with you, like a photograph or a file, I could copy it onto this
USB drive and then give it to you and then you'd copy it to your computer.
So sneaker net, the original type of networking, if you like, is where a human being would take a
resource.
I'd copy a file or a photograph onto this USB drive.
I'd walk to your computer and then give it to you and share the resource with you.
But that's not very effective.
It's not scalable, doesn't work that well.
You let's be honest, most humans would be too lazy to have to walk around the office to share files.
It's much easier just to share files using a digital transmission mechanism or medium, and they're
different types of digital transmission mechanisms.
Why are we doing this?
We are trying to share a resource between what in this definition is called a node, and they define
that as a computing device.
So a node is a computing device and there are many types of computing devices.
We could have windows, laptops, we could have Mac books, we could have phones, we could have servers.
Those are often the devices that most consumers will think about.
And I've mentioned printers already has another one.
But in networking we have specialized devices such as hubs, switches, routers and firewalls to name
a few.
So stepping back a second, why do we have a computer network we want to share resources, which could
be a printer, could be a file, could be a video.
So four videos are very popular these days.
You watching this video through a computer network?
I'm sharing this information with you using a data link in the Wikipedia definition.
They talk about a data link being a physical cable such as trusted pay fiber optic cables, Wi-Fi or
some type of data link where I'm sharing information with you.
So the big idea here is I'm sharing a resource with you and I need a way.
To get that to you, you need a device that could receive the resource, we need some kind of transmission
media, which could be physical cables or it could be wireless.
So the idea is, rather than having to physically transport a file on a USB drive or in the very, very
old days using a floppy disk, we use a cable or some kind of mechanism to transmit data from one device
to another or from one device to many devices.