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When we talk about network resources, we have

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to think about how data is being moved around the network.

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We break this down into two main models,

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the client server model and the peer-to-peer model.

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Let's start out talking about the client-server model.

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The client-server model is going to use a dedicated server

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to provide access to files, scanners, printers,

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and other resources on the network.

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Now, administration and backup is pretty easy here,

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because we have one central machine, this server,

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that all the resources are sitting on,

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and so we can go ahead and backup that server

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and we've backed up all the files.

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We can configure that server

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and we've configured all the accesses, right?

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This makes the client server model one

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of the main choices we use in business networks.

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Now, when we look at the benefits of a client-server model,

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it gives us that centralized administration.

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There is one or a few key servers

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when we can focus all of our effort there,

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that gives us easier management,

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again, because it's all in one or two places

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because we have those few key servers that we can manage,

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and it gives us better scalability,

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because I can have all of my stuff in one place,

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and if I need to expand, I can actually expand outward using

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that through a cloud architecture

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or some other additional servers,

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and depending on how I need to do that,

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and this will allow me to put things in tandem

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using load balancing,

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and it'll gimme a lot more benefits than try

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to run things under the peer-to-peer model.

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Now, some of those drawbacks to a client server

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is that it costs more money

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because it requires dedicated hardware

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and dedicated operating system software.

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So you might have to have something like Windows on there

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or a Unix or Linux build, or something like that.

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And this takes a highly-specialized skillset

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to run all of these things.

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And so it requires these dedicated resources,

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whether they're machines or software,

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or that operating system, as well

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as personnel who know how to use it.

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So that's kind of the bad things when we talk

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about a client-server model.

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With all that said, client-server is still the leading model

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that we use in business networks.

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Now, let's look at the other side, the peer-to-peer model.

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This is where peers or other machines, like laptops

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and desktops, can share resources together directly.

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The administration and backup is very difficult

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because all the files are located on different machines

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in different places.

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For example, if I wanted to share some PowerPoint slides

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with you and you're sharing some Excel files with me,

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these files are on both of our machines,

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and now we're going to have to back up both machines

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and manage both of them,

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and this is going to give us two sets of permissions on them

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and all that other management.

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You see how this redundancy in that work

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where we have to do multiple things in multiple places.

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Now, if I took that

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and I scaled that up to 50 machines, that gets kind

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of being a nightmare, right?

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Because we're going to have a lot of work there.

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That's the big drawback to peer-to-peer.

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Now, where is peer-to-peer useful?

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Well, if you think back a decade ago,

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there was a software out there called Napster,

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and this was a peer-to-peer file sharing program.

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Now, it happened to be used for a lot

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of illegal activity like downloading music without copyright

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and those type of things, but the concept behind it

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is what we want to focus on here.

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Each person who was part

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of the network gave and received files.

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It was a peer-to-peer sharing network.

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Now, the benefits of peer-to-peer

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was it was low-cost.

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There was no infrastructure, no specialized hardware,

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no dedicated hardware, none of that stuff,

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because there's just software

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and it allowed everyone to talk to each other as they wanted

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to and share files.

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You could pick a folder your hard drive

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and share that out with the world.

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This allowed you to create resources

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and networks wherever we wanted to.

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So this was kind of the thing here

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is that there was no specialized operating system,

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no dedicated resources, and it was very low to start up.

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Now, if I wanted to create a network

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and we had five computers, I might just turn one

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of them into a file sharing off my local laptop,

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and you can all access it.

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It would be no problem.

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That's the idea of a peer-to-peer.

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But there's also some drawbacks

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because if my machine is off now, you can't access anything.

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Whereas if I had a centralized server, you still could

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because that server would be on 24 hours

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a day, seven days a week.

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Now, what are some of the drawbacks?

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Well, the biggest one is decentralized management.

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Everyone can own and control their own machine

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and decide what they're sharing

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and what they're not sharing.

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This becomes extremely inefficient when you deal

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with large networks or business networks,

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and it has horrible scalability.

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So if I wanted to run a peer-to-peer network

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for an organization the size of Facebook,

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it just wouldn't work.

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It would be horrible.

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You'd have

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to have centralized management for stuff.

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Otherwise, when things get large, they get lost.

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And so in business networks,

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we are really going to focus on this client-server model

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over peer-to-peer for the exam.

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You do want to understand what a client-server model

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is and a peer-to-peer model, and really what the benefits

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and drawbacks are for each of them.

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All the benefits on the client server model are drawbacks

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on peer-to-peer, and all the drawbacks

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on client-server model

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are actually benefits on peer-to-peer.

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They're basically opposites of each other.

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If you remember that, you'll do great on the exam.