All language subtitles for 4. What is a Computer

Everybody uses terms like CPU, RAM, hard drives.
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We've heard these terms but in this episode I want to talk about what really is a computer.
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Now in order to have a computer...remember why we have them in the first place,
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it's to get stuff done.
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We do things like generate spreadsheets or edit videos or control traffic or play games. No matter what
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it is,
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the whole function of a computer is to get something done, either work or play.
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So the cornerstone of any computer you're going to have out there are the CPUs.
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So here's a couple of CPUs I've got laying here.
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Now, a lot of times we'll say a CPU is like the "brain" of the computer and it's really more like a really
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super high-speed calculator.
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And what we do is we write programs that the processor can then do stuff with to manipulate peripherals
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and create these things called files to get stuff done.
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So we have these huge things called programs.
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Now programs can be applications like, say, Microsoft Word or Edge browser something like that. Or it could
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be a utility that helps us get on a network.
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But they're all programs.
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So when your computer's turned off, those programs have to sit someplace and that's what these guys are
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all about.
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This is mass storage.
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So in this particular case this is called an M.2 SSD solid state drive and it's stores stuff statically.
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And this is a old school, but still very popular hard drive, it's got spinning platters in there.
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The only thing these guys do is they store data, whether that data is a program or a Microsoft Word document.
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When you're not using it, when you're on your computer doing whatever you're doing, and suddenly you double
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click on an icon to, say, start up Microsoft Word, a lot of things start to take place.
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First of all, your computer, the CPU, knows how to talk to the hard drive.
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You'll say, "Go get that Microsoft Word." Now, hard drives are fast, but the problem is, they're not nearly
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as fast as the CPUs.
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So while we are already running a program, what we're really doing is we're taking a copy of that program
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off of the mass storage and we're putting it on to our RAM, or random access memory.
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So when a program is running, it is stored in RAM.
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RAM is super fast, not quite as fast as a CPU, but it's very very fast.
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The only downside is, as compared to a hard drive,
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RAM is very very expensive.
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So we only use RAM when we're running a program.
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So what will happen is the CPU will then copy, let's say, Microsoft Word copies the Microsoft Word program
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onto RAM and then it begins running the Word program.
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Now the Word program basically sits there with a nice white screen waiting for you to press buttons
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on your keyboard.
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"Hi Mom, I am fine.
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Love, Mike."
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So the program itself is monitoring peripherals. In this particular case, it's monitoring the keyboard
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and as each letter gets pressed to start showing up on the screen and you write yourself a letter and
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then you go through a process of saving your data, saving a file.
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So what'll happen is then the CPU will then instruct the data that you've written on RAM...it doesn't
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go to the hard drive automatically....
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the data you've written on RAM, you hit "File > Save" and then that's copied also to your mass storage. So mass
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storage stores two very different things.
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Number one, it's storing the programs that aren't in use.
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And number two, it stores our data: our pictures, our Word documents, our saved games whatever it might
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be.
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So we go through this process back and forth and back and forth. In order to be a computer,
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you have to have a processor,
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you have to have RAM, and you have to have mass storage.
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There's no exception to that.
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The other thing, and we'll cover this in another episode, is you need some kind of program that is the
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king of all programs and we call these operating systems.
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So, even though in this series I use desktop computers a lot,
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big desktops,
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the reason I use them is because, well, they're big and it's easy for me to show you RAM and CPUs and
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a hard drive and stuff like that.
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But what I need you to get in mind right away is that computers aren't just desktops.
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Take a look over here.
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This is a perfectly good little laptop computer. Inside this laptop is a CPU. Inside this laptop is
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is mass storage. Inside this laptop is lots and lots of RAM and video and a keyboard and all kinds
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of other stuff too.
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This is a computer
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here's my little Apple tablet.
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Inside this Apple tablet is a CPU. Inside this tablet is RAM. Inside this tablet is mass storage.
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There's even an operating system all built in to this one little tablet.
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But don't let it stop there.
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Here's an Android phone.
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This Android phone has a CPU.
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It has RAM.
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It has mass storage.
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It has an operating system.
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It's all built into that.
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I mean let's go crazy here.
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Ever heard the term "Internet of Things?"
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Here's a little device called a Raspberry Pi.
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This is a little teeny tiny computer but, heck, this thing's even got USB ports and a network connection
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and all that type of stuff on this particular guy.
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We've got a CPU, RAM, mass storage, everything in fact on this guy.
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It's all actually put onto one individual chip.
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We use the term "system on a chip" to define that type of thing.
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Computers are everywhere.
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The washer and dryer in my house is a full computer system. I could actually turn on the dryer using
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my phone.
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You got...use cameras or anything like that?
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This camera has a CPU, RAM, operating system.
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Everything is all in this camera.
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How about the routers or the wireless access points that we use in our home?
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These guys are also complete computers. Inside this computer is going to be a CPU, RAM, storage, an
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operating system...everything that we need to be a complete computer. So be careful when you use the word
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"computer."
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The computers have taken over happily because it sure makes our lives convenient. And everything from the
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big desktops, which we'll be concentrating on in this series, down to the smallest little camera, or in
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my case washer and dryer, is all a computer.
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All you need is a CPU, RAM, mass storage, and something called an operating system.