跟讀練習: Introduction to Networking | Network Fundamentals Part 1 (Revised) - 通過影片學習英語口語

Hello and welcome to my Introduction to  Networking video series. My name is Luke and it is my goal to help you get a solid foundation  in understanding what networks are all about.

This video series is perfect for anyone  who is completely new to networking.

Whether you're interested in a career  in it or you're just simply curious, this is the right place for you. These videos can  also help you if you're struggling with a college or university course and you just need a little  bit more understanding to get across the line.

Now throughout this series, I'm going to assume  that you have no networking experience at all. The goal of my work here is to lay a solid foundation  that you can then build on throughout your career.

In this video, we're going to start  by understanding simply what a network actually is. So if you're ready, let's now  consider this question, what is a network?

A network may already be familiar to you. Maybe  you have your own network at home or perhaps you've helped someone to run a network at a school  or at your job. But can you really tell me what a network actually is? I would like to give you  this little challenge now. Please pause this video and think to yourself, how can we define  what a network actually is? I would like you to pretend that you need to explain this to someone  who knows absolutely nothing about networking.

Okay, so how did you go? Did you get a  definition you're happy with? Well if you did, congratulations! Well done! For those of you  who are completely new to networking, here is a little definition that I came up with. I define  this as "a system that allows multiple devices to communicate with one another". Let's take this  definition and build on this a little bit now.

At work or at home you will have a bunch of  devices. These are things like computers, printers, TVs and so on. And you connect  all of these together by means of a network.

When the devices are connected, they're able to  share information between each other. This could be something simple, like sending a document to  a printer, sending an email or streaming a video.

This can also be used for sharing access to  the internet. Now mostly users on a network are unaware of the network they're using. As long  as they can browse the Net, or do their job, access Instagram or whatever it is they like  to use, then they're usually happy. They don't need to know the specifics of it. Now for all  these devices to communicate, they do need to be connected together somehow. Now one way  is to plug cables into all these devices and connect them to another special device, called a  switch. I will explains what is a switch later on, for now just think of a switch as some networking  equipment that we use to connect things together.

Let's take a little time now to think about  how we connect our devices to this switch.

Think of a computer lab in a school. The switch  that these devices connect to, these computers, will likely be in a different room or  maybe it's mounted up on a wall somewhere.

In either case, the computer in the lab will  connect to the network by using a wall socket.

Another cable from behind this wall socket,  will run through the wall to another location, this then connects to something that we  call a patch panel. And you can see one here on your screen right now. As I said  before, this may be in a cabinet somewhere on the wall. It might be in the same room,  or it might be in another room entirely.

So each wall socket that we plug a computer  into, connects back to one of these ports on the patch panel. We can then connect each  of these ports directly into the switch.

Now, that's one of the ways that we can keep  our cabling nice and tidy and organized.

You might even have a switch at home. Most  homes don't have the luxury of wall sockets, so often we have devices directly connected to  the switch. Remember of course though, there's a lot more detail to switches. I will tell you a  bit more about those in future, as we get to that.

Devices can also be connected together  wirelessly. A common way to do this is with a Wireless Access Point. A wireless  network like this is often called Wi-Fi.

An example of this is when you're using your  phone. It's really impractical and often impossible to cable it into your network,  so wireless is by far your best option.

The access point, that is, the Wireless Access  Point, is basically the same thing as a switch, but it doesn't use cables. More than one device  can connect to the access point at a time, but we don't have all the messy cabling  that we get sometimes with a switch.

We can also connect a switch and an  access point together with a cable.

In this way, devices that use cables, which  are 'wired devices', can also be a part of the same network, as devices that don't  use cables, which are 'wireless devices'.

So having both wired switches and Wireless  Access Points gives us more connection options.

For example, imagine that you have a  laptop and you're working in an office.

You may connect it to the network using a  cable when you're sitting down at your desk, where you do most of your work. But  sometimes, you'll need to give a presentation in the boardroom and for this,  when you have this meeting in the boardroom, you remove the cable and you connect your laptop  to Wi-Fi. So you don't have cables connected everywhere, which makes things a lot easier  for you as a user to connect to the network Whether our devices are wired or wireless, the  goal is still the same. We want to be able to have one device send information to another device.  But for this to work properly, the sender and the receiver both need to understand each other.  We could say that they both need to speak the same language. Now in the network, speaking the same  language means that the devices need to agree on how data is sent, how it is received, how it  is organized, and how it is handled. Basically, they have a process on how to handle this  information and they have to agree on the same process. Now this language that they speak  is called a Protocol, and there are a lot of different protocols out there. The ones we use  will vary depending on what's needed at the time.

Network Software and Hardware are designed with  these protocols in mind. You will often hear of protocols such as Ethernet and TCP. These ones are  used for sending information from one device to another. But you may also hear of protocols like  HTTP, which is specifically used for accessing websites. Or you might hear of SMTP, which is  specifically used for sending and receiving email.

The truth is, usually we have several protocols  working together to get a common task done.

We'll take a bit of a deeper look at this sometime  in a future video. I really want to help you to understand networking, so throughout this video  series, I would like to offer the opportunity to test your understanding, which will help you to  find areas that perhaps you haven't understood as well as others. To do this, I have quiz  questions, like the ones you can see here.

These are intended, not to be simple multiple  choice questions ,but ones that are well, they make you think! They make you really work  out if you've understood what you've learned.

The answer to these, as well as some  explanations of them are available on my website - networkdirection.net and you  can see the link to that here on the screen.

So congratulations! You have made it  through the very first video in this series and I really hope that you've enjoyed  this and I hope that you'll follow along with me in my next video, where we will  investigate different types of Networks.