-: In the last video, we talked about why we use networks. 2 2
And the whole purpose is to get data 3 3
from one place to another, from one machine to another. 4 4
Now whether that's carrying voice, video or data, 5 5
it's going to have to get across the network somehow. 6 6
Now what comprises our networks? 7 7
Well, that's what we're going to answer in this video. 8 8
We're going to talk about 9 9
all of the different network components, 10 10
things like clients and servers, hubs, 11 11
wireless access points, switches, 12 12
routers, media and WAN links. 13 13
Now some of those terms probably look familiar 14 14
and others may not. 15 15
So we're going to go through each one of them 16 16
individually in this lesson, 17 17
the first one we have is clients. 18 18
And these are the devices that our end user 19 19
is going to access the network with. 20 20
This can be something like a workstation, a laptop, 21 21
a tablet, a smartphone, a smart TV, a server, 22 22
or any other terminal device. 23 23
Even your wifi enabled thermostat like a nest, 24 24
this is considered a client. 25 25
This can be any device that connects to the network. 26 26
And we're going to use this big bucket term 27 27
called client to describe all of them. 28 28
The next component we have is what's known as a server. 29 29
Now a server is something that provides resources 30 30
to the rest of your network. 31 31
Now, if you're at work, you're probably familiar 32 32
with an email server or a file server, right? 33 33
And there's different servers 34 34
that provide different functions. 35 35
You may have a web server or an email server 36 36
or a file server or a chat server 37 37
a or print server and all sorts 38 38
of other different kinds of servers. 39 39
These can be dedicated hardware, 40 40
or they can be a specialized type of software 41 41
that the device uses, and that takes it 42 42
and allows it to act like a server for us. 43 43
We'll talk more about these 44 44
as we go through the different models, 45 45
whether it's going to be a client server model 46 46
or a peer to peer model, but for right now, 47 47
I just want you to be familiar with the term server. 48 48
The next component we're going to discuss is called a hub. 49 49
Now, a hub is a piece of old technology 50 50
that we really don't use in our networks anymore, 51 51
but we're still going to cover it because the exam covers it. 52 52
When I was growing up in the industry, 53 53
we used hubs everywhere. 54 54
Hubs were an easy way for us to connect network devices, 55 55
such as clients and servers and put them together. 56 56
They could be interconnected to provide 57 57
even more ports if I needed to, 58 58
by plugging one port of one hub 59 59
into another port of another hub, 60 60
and this would create a daisy chain effect. 61 61
The problem is, that this could lead 62 62
to increased network errors. 63 63
Basically when you have a hub, 64 64
information comes in one port of the hub 65 65
and then gets spit out all of the other ports. 66 66
So if you have a four port hub, one person is talking 67 67
and it rebroadcasts it out to the other three people. 68 68
This isn't a big deal when you have a four port hub, 69 69
but if you have a 48 port hub, 70 70
now when one person is talking, 71 71
the other 47 people have to listen to it too. 72 72
We're going to cover hubs a lot more in depth later on 73 73
because they're the backbone of networking 74 74
and switches that we're going to talk about 75 75
and use in our networks today 76 76
are actually a second generation version of hubs 77 77
that combine hubs with another device called a bridge. 78 78
Now, the next component we're going to talk about 79 79
is a wireless access point. 80 80
Wireless access points are devices 81 81
that allow wireless devices 82 82
to connect into your wired network. 83 83
So if you're using your laptop or your smartphone right now, 84 84
and you're connecting over wifi, 85 85
you're actually into a wireless access point. 86 86
These are commonly used in homes, 87 87
small businesses, colleges, 88 88
and even large enterprise networks. 89 89
Effectively, a wireless access point is a wireless hub. 90 90
Whatever is broadcast out one way, 91 91
goes out the other way as well. 92 92
We're going to talk a lot more about wireless access points 93 93
when we get to the wireless devices section 94 94
later on in this course. 95 95
The next component we have is called a switch. 96 96
Now, a switch is a smarter version of a hub. 97 97
It connects network devices, such as clients 98 98
and servers together, just like a hub did, 99 99
but there's a big difference here. 100 100
Switches can learn which devices are on which ports. 101 101
So instead of taking it in one port 102 102
and pushing out the other ports, two, three and four, 103 103
as we did with a four port hub, 104 104
a switch will take it in on port one 105 105
and then send it out only to port two, three or four, 106 106
whichever one it's trying to talk to. 107 107
And so I like to think about this, 108 108
instead of us being in a room and broadcasting 109 109
our message to everyone in the class, 110 110
I take the single person I want to talk to, 111 111
put them into a closet with me and then we talk over there. 112 112
That way we're not disturbing everybody else. 113 113
Now this is the big benefit of a switch. 114 114
And we're going to talk a lot more about switches later on 115 115
when we get into the ethernet fundamental section. 116 116
Switches are only going to forward traffic 117 117
received from one port to the destination port. 118 118
And so we call these smart hubs essentially, right? 119 119
Because they act like hubs, but there are a lot smarter, 120 120
but instead we're going to actually call them switches 121 121
'cause that's the right term. 122 122
These are they going to be providing you with more security 123 123
and more efficient use of bandwidth than a hub did. 124 124
And this is going to give us a lot better use 125 125
inside of our networks. 126 126
The next device we have to cover is called a router. 127 127
Now a router is used 128 128
to connect two different networks together. 129 129
They're going to intelligently make forwarding decisions 130 130
from one network to the next, based on its logical address, 131 131
which we refer to as an IP address 132 132
or internet protocol address. 133 133
Most modern routers are going to rely on IP. 134 134
Although there are other 135 135
routing protocols out there as well. 136 136
We're going to talk a lot more about routers. 137 137
In fact, we have an entire section dedicated to routing. 138 138
Next, we have media. 139 139
Now media is what we use to connect two devices 140 140
or a device to a switch port. 141 141
These can be things like copper cable, 142 142
fiber optic cable, or even radio waves if you're using wifi. 143 143
It doesn't really matter what the media type is. 144 144
But we have to understand that media 145 145
is the things that connect everything. 146 146
If there's a break in the cable or the media, 147 147
your networks aren't going to work right. 148 148
Each type of media has its own strengths and weaknesses. 149 149
And we're going to talk all about those later in the course, 150 150
for example, copper is very cheap to use, 151 151
but it can't go very far. 152 152
Fiber optic on the other hand can go really far, 153 153
but it costs a lot of money. 154 154
Each one has its own bandwidth limitations, 155 155
capacity limitations and distance limitations. 156 156
Now we're going to get into those specifics 157 157
later on in the course, 158 158
because you're going to have to memorize each of them, 159 159
including down to how many feet they can cover. 160 160
For example, if I'm talking about a copper cable, 161 161
how long it can go, 162 162
or a fiber optic cable, how long it can go. 163 163
And we'll talk about that later on 164 164
when we get into the ethernet section down the road. 165 165
The last component we need to talk about 166 166
is a wide area network link, or a WAN link. 167 167
Now a WAN link is going to physically connect 168 168
two networks together that are geographically dispersed. 169 169
So when you look at the internet, 170 170
it's really just a big series of WAN links. 171 171
If I go to your house right now, 172 172
and I connect my laptop to your network 173 173
and you didn't have a WAN link, 174 174
we would only be able to talk inside your house. 175 175
We wouldn't be able to make it to the outside world 176 176
and go to Facebook or Google, or even back to my house. 177 177
That's what a WAN link allows you to do. 178 178
Whether you're using it lease line, a DSL line, 179 179
a cable line, a fiber optic line, 180 180
a cellular, satellite, microwave, it really doesn't matter. 181 181
All of those are WAN links. 182 182
It's your connection to the outside world. 183 183
And it has to be routed through a router, 184 184
back into your network. 185 185
This is going to connect your internal network 186 186
to the external networks, and when we do this, 187 187
like we take your small office, 188 188
your home office and we connect it to the internet, 189 189
that's exactly what we're doing. 190 190
So we'll talk more about WAN links later, 191 191
because we have another entire section dedicated to those.